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{{Short description|Swiss-American naturalist (1807–1873)}}
{{Redirect|Agassiz}}
{{Use mdy dates|date=May 2018}}
{{Infobox scientist
| name              = Louis Agassiz
| honorific_suffix  = {{post-nominals|country=GBR|size=100%|ForMemRS}}
| image             = Louis Agassiz H6.jpg
| caption           = Agassiz, c. 1865
| birth_date        = {{birth date|1807|05|28|mf=y}}
| birth_place       = [[Haut-Vully|Môtier]], [[Canton of Fribourg]], [[Switzerland in the Napoleonic era#Act of Mediation|Swiss Confederation]]
| death_date        = {{death date and age|1873|12|14|1807|05|28|mf=y}}
| death_place       = {{nowrap|[[Cambridge, Massachusetts]], U.S.}}
| residence         = 
| spouse            = {{plainlist|
* Cecilie Braun (m. 1833; died 1848)
* [[Elizabeth Cabot Agassiz|Elizabeth Cabot Cary]] (m. 1850)
}}
| citizenship       = United States
| children          = 3, including [[Alexander Emanuel Agassiz|Alexander]] and [[Pauline Agassiz Shaw|Pauline]]
| field             = {{plain list|
* [[Paleontology]]
* [[Glaciology]]
* [[Geology]]
* [[Natural history]]
}}
| author_abbrev_zoo = Agassiz, Ag., L. Ag., Agass.
| education         = [[University of Erlangen-Nuremberg]] ([[PhD]])<br />[[University of Munich]]
| workplaces        = [[University of Neuchâtel]]<br />[[Harvard University]]<br />[[Cornell University]]
| awards            = [[Wollaston Medal]] (1836)
| doctoral_advisor  = [[Carl Friedrich Philipp von Martius]]
| academic_advisors = [[Ignaz Döllinger]], [[Georges Cuvier]]
| notable_students  = [[William Stimpson]], [[William Healey Dall]], [[Carl Vogt]],<ref name="Rupke 54">Nicolaas A. Rupke, ''Alexander von Humboldt: A Metabiography'', University of Chicago Press, 2008, p. 54.</ref> [[David Starr Jordan]]
| known_for         = [[Ice age]], [[Polygenism]]
| signature         = Appletons' Agassiz Jean Louis Rudolphe signature.svg
}}

'''Jean Louis Rodolphe Agassiz''' ({{IPAc-en|ˈ|æ|ɡ|ə|s|i}} {{respell|AG|ə|see}}; {{IPA|fr|aɡasi|lang}}) FRS (For) [[FRSE]] (May 28, 1807 – December 14, 1873) was a Swiss-born American biologist and geologist who is recognized as a scholar of Earth's [[natural history]].

Spending his early life in [[Switzerland]], he received a [[PhD]] at [[Erlangen]] and a medical degree in [[Munich]]. After studying with [[Georges Cuvier]] and [[Alexander von Humboldt]] in Paris, Agassiz was appointed professor of [[natural history]] at the [[University of Neuchâtel]]. He emigrated to the [[United States]] in 1847 after visiting [[Harvard University]]. He went on to become professor of zoology and geology at Harvard, to head its [[Lawrence Scientific School]], and to found its [[Museum of Comparative Zoology]].

Agassiz is known for observational data gathering and analysis. He made institutional and scientific contributions to zoology, geology, and related areas, including multivolume research books running to thousands of pages. He is particularly known for his contributions to [[ichthyological]] classification, including of extinct species such as [[megalodon]], and to the study of [[historical geology]], including the founding of [[glaciology]].

His theories on human, animal and plant [[polygenism]] have been criticised as implicitly supporting [[scientific racism]].

==Early life==
{{further|Agassiz family}}
Louis Agassiz was born in the village of {{ill|Môtier|fr|Môtier}} (now part of [[Haut-Vully]] which merged into [[Mont-Vully]] in 2016) in the Swiss [[Canton of Fribourg]].<ref name="BDA1906p60">{{harvnb|Johnson|1906|p=60}}</ref> He was the son of a pastor,<ref>Frank Leslie's new family magazine. v. 1 (1857), p. 29</ref> Louis Rudolphe and his wife, Rose Mayor.

His father was a [[Protestant]] clergyman, as had been his progenitors for six generations, and his mother was the daughter of a [[physician]] and an intellectual in her own right, who had assisted her husband in the education of her boys.<ref name="BDA1906p60" /> Louis Agassiz was educated at home<ref name="BDA1906p60" /> until he spent four years at secondary school in [[Bienne]], which he entered in 1818 and completed his elementary studies in [[Lausanne]]. Agassiz studied at the Universities of [[University of Zurich|Zürich]], [[Ruprecht Karl University of Heidelberg|Heidelberg]] and [[Ludwig Maximilian University of Munich|Munich]]. At the last one, he extended his knowledge of [[natural history]], especially of [[botany]]. In 1829, he received the degree of [[doctor of philosophy]] at [[Friedrich-Alexander-University, Erlangen-Nuremberg|Erlangen]] and, in 1830, that of [[doctor of medicine]] at Munich.{{sfn|Woodward|1911|p=367}} 
Moving to Paris, he came under the tutelage of [[Alexander von Humboldt]] and later received his financial benevolence.<ref>Andrea Wulf, ''The Invention of Nature: Alexander von Humboldt's New World''. New York: Alfred A. Knopf 2015, p. 250</ref> Humboldt and [[Georges Cuvier]] launched him on his careers of respectively geology and zoology.<ref name="AMB">{{Cite AMB1920|wstitle=Agassiz, Jean Louis Rudolph}}</ref> Ichthyology soon became a focus of Agassiz's life's work.<ref name="AMB" />

==Early work==
[[File:Jean Louis Agassiz 1870.jpg|left|thumb|Agassiz in 1870]]
In 1819 to 1820, the German biologists [[Johann Baptist von Spix]] and [[Carl Friedrich Philipp von Martius]] undertook an expedition to [[Brazil]]. They returned home to Europe with many natural objects, including an important collection of the [[freshwater fish]] of Brazil, especially of the [[Amazon River#Fish|Amazon River]]. Spix, who died in 1826, likely from a tropical disease, did not live long enough to work out the history of those fish, and Martius selected Agassiz for this project.

Agassiz threw himself into the work with an enthusiasm that would go on to characterize the rest of his life's work. The task of describing the Brazilian fish was completed and published in 1829. It was followed by research into the history of fish found in [[Lake Neuchâtel]]. Enlarging his plans, he in 1830 issued a prospectus of a ''History of the Freshwater Fish of Central Europe''. In 1839, however, the first part of the publication appeared, and it was completed in 1842.{{sfn|Woodward|1911|p=367}}

In November 1832, Agassiz was appointed professor of natural history at the [[University of Neuchâtel]], at a salary of about US$400 and declined brilliant offers in Paris because of the leisure for private study that that position afforded him.<ref name="BDA1906p61">{{harvnb|Johnson|1906|p=61}}</ref> The [[fossil fish]] in the rock of the surrounding region, the [[slate]]s of [[Glarus]] and the [[limestone]]s of Monte [[Bolca]], soon attracted his attention. At the time, very little had been accomplished in their scientific study. Agassiz as early as 1829, planned the publication of a work. More than any other, it would lay the foundation of his worldwide fame. Five volumes of his ''Recherches sur les poissons fossiles'' (''Research on Fossil Fish'') were published from 1833 to 1843. They were magnificently illustrated, chiefly by [[Joseph Dinkel]].<ref>{{cite web | url = https://www.geolsoc.org.uk/Geoscientist/Archive/February-2013/Agassizs-Fossil-Fish | title = Agassiz's Fossil Fish | publisher = The Geological Society}}</ref> In gathering materials for that work, Agassiz visited the principal museums in Europe. Meeting Cuvier in Paris, he received much encouragement and assistance from him.{{sfn|Woodward|1911|p=367}}

In 1833, he married Cecile Braun, the sister of his friend [[Alexander Braun]] and established his household at [[Neuchâtel]]. Trained to scientific drawing by her brothers, his wife was of the greatest assistance to Agassiz, with some of the most beautiful plates in ''fossil'' and ''freshwater'' fishes being drawn by her.<ref name="BDA1906p61" />

[[File:Louis Aggasiz and Benjamin Peirce.jpg|thumb|upright=1.2|With [[Benjamin Peirce]] ]]
Agassiz found that his palaeontological analyses required a new ichthyological classification. The fossils that he examined rarely showed any traces of the soft tissues of fish but instead, consisted chiefly of the teeth, scales, and fins, with the bones being perfectly preserved in comparatively few instances. He therefore adopted a classification that divided fish into four groups (ganoids, placoids, cycloids, and ctenoids), based on the nature of the scales and other dermal appendages. That did much to improve fish [[taxonomy (biology)|taxonomy]], but Agassiz's classification has since been superseded.{{sfn|Woodward|1911|p=367}}

With Louis de Coulon, both father and son, he founded the ''Societé des Sciences Naturelles'', of which he was the first secretary and in conjunction with the Coulons also arranged a provisional museum of natural history in the orphan's home.<ref name="BDA1906p61" /> Agassiz needed financial support to continue his work. The [[British Association for the Advancement of Science|British Association]] and the [[Earl of Ellesmere]], then [[Francis Egerton, 1st Earl of Ellesmere|Lord Francis Egerton]], stepped in to help. The 1290 original drawings made for the work were purchased by the Earl and presented by him to the [[Geological Society of London]]. In 1836, the [[Wollaston Medal]] was awarded to Agassiz by the council of that society for his work on fossil ichthyology. In 1838, he was elected a foreign member of the [[Royal Society]]. Meanwhile, [[invertebrate]] animals engaged his attention. In 1837, he issued the "Prodrome" of a monograph on the recent and fossil [[Echinodermata]], the first part of which appeared in 1838; in 1839–1840, he published two quarto volumes on the fossil echinoderms of Switzerland; and in 1840–1845, he issued his ''Études critiques sur les mollusques fossiles'' (''Critical Studies on Fossil Mollusks'').{{sfn|Woodward|1911|p=367}}

Before Agassiz's first visit to England in 1834, [[Hugh Miller]] and other geologists had brought to light the remarkable fossil fish of the [[Old Red Sandstone]] of the northeast of Scotland. The strange forms of ''[[Pterichthys]]'', ''[[Coccosteus]]'', and other genera were then made known to geologists for the first time. They were of intense interest to Agassiz and formed the subject of a monograph by him published in 1844–1(45: ''Monographie des poissons fossiles du Vieux Grès Rouge, ou Système Dévonien (Old Red Sandstone) des Îles Britanniques et de Russie'' (''Monograph on Fossil Fish of the Old Red Sandstone, or Devonian System of the British Isles and of Russia'').{{sfn|Woodward|1911|p=367}} In the early stages of his career in Neuchatel, Agassiz also made a name for himself as a man who could run a scientific department well. Under his care, the University of Neuchâtel soon became a leading institution for scientific inquiry.{{citation needed|date=May 2018}}

[[File:Louis Agassiz H3.jpg|thumb|upright|Portrait photograph by [[John Adams Whipple]], ''circa'' 1865]]
In 1842 to 1846, Agassiz issued his ''Nomenclator Zoologicus'', a classification list with references of all names used in zoological genera and groups.

He was elected as a member of the [[American Philosophical Society]] in 1843.<ref>{{Cite web|title=APS Member History|url=https://search.amphilsoc.org/memhist/search?creator=&title=&subject=&subdiv=&mem=&year=1843&year-max=1843&dead=&keyword=&smode=advanced|access-date=2021-04-12|website=search.amphilsoc.org}}</ref>

==Ice age==
[[File:Agassiz, Louis – Nouvelles études et expériences sur les glaciers actuels, 1847 – BEIC 12025435.jpg|thumb|upright|''Nouvelles études et expériences sur les glaciers actuels'', 1847]]

The vacation of 1836 was spent by Agassiz and his wife in the little village of [[Bex]], where he met [[Jean de Charpentier]] and [[Ignaz Venetz]]. Their recently announced [[Ice_age#History_of_research|glacial theories]] had startled the scientific world, and Agassiz returned to Neuchâtel as an enthusiastic convert.<ref name="BDA1906p62">{{harvnb|Johnson|1906|p=62}}</ref> In 1837, Agassiz proposed that the Earth had been subjected to a past [[ice age]].<ref name="evans 1887">E.P. Evans: "The Authorship of the Glacial Theory", ''North American review'' Volume 145, Issue 368, July 1887. Accessed on January 24, 2018. {{jstor|25101263}}</ref> He presented the theory to the [[Helvetic Society]] that ancient glaciers flowed outward from the Alps, and even larger glaciers had covered the plains and mountains of Europe, Asia, and North America and smothered the entire [[Northern Hemisphere]] in a prolonged ice age. In the same year, he was elected a foreign member of the [[Royal Swedish Academy of Sciences]]. Before that proposal, [[Johann Wolfgang von Goethe|Goethe]], [[Horace-Bénédict de Saussure|de Saussure]], Ignaz Venetz, Jean de Charpentier, [[Karl Friedrich Schimper]], and others had studied the [[glaciers]] of the Alps, and Goethe,<ref name="goethe">{{cite book |last=Cameron |first=Dorothy |year=1964 |title=Early discoverers XXII, Goethe-Discoverer of the ice age. Journal of glaciology |url=https://www.cambridge.org/core/services/aop-cambridge-core/content/view/7883A16803630B43E40A1364C62EEBD7/S0022143000018761a.pdf/div-class-title-early-discoverers-xxii-goethe-discoverer-of-the-ice-age-div.pdf |access-date=September 10, 2023 |archive-date=July 28, 2018 |archive-url=https://web.archive.org/web/20180728091738/https://www.cambridge.org/core/services/aop-cambridge-core/content/view/7883A16803630B43E40A1364C62EEBD7/S0022143000018761a.pdf/div-class-title-early-discoverers-xxii-goethe-discoverer-of-the-ice-age-div.pdf |url-status=bot: unknown }}</ref> Charpentier, and Schimper<ref name="evans 1887" /> had even concluded that the [[glacial erratic|erratic]] blocks of alpine rocks scattered over the slopes and summits of the [[Jura Mountains]] had been moved there by glaciers. Those ideas attracted the attention of Agassiz, and he discussed them with Charpentier and Schimper, whom he accompanied on successive trips to the Alps. Agassiz even had a hut constructed upon one of the [[Aar Glaciers]] and for a time made it his home to investigate the structure and movements of the ice.{{sfn|Woodward|1911|p=367}}

Agassiz visited England, and with [[William Buckland]], the only English naturalist who shared his ideas, made a tour of the [[British Isles]] in search of glacial phenomena, and became satisfied that his theory of an ice age was correct.<ref name="BDA1906p62" /> In 1840, Agassiz published a two-volume work, ''Études sur les glaciers'' ("Studies on Glaciers").<ref>[http://fr.wikisource.org/w/index.php?title=%C3%89tudes_sur_les_glaciers&oldid=297457 Louis Agassiz: ''Études sur les glaciers'', Neuchâtel 1840. Digital book on Wikisource]. Accessed on February 25, 2008.</ref> In it, he discussed the movements of the glaciers, their [[moraines]], and their influence in grooving and rounding the rocks and in producing the striations and ''roches moutonnées'' seen in Alpine-style landscapes. He accepted Charpentier and Schimper's idea that some of the alpine glaciers had extended across the wide plains and valleys of the [[Aar]] and [[Rhône]], but he went further by concluding that in the recent past, Switzerland had been covered with one vast sheet of ice originating in the higher Alps and extending over the valley of northwestern Switzerland to the southern slopes of the Jura. The publication of the work gave fresh impetus to the study of glacial phenomena in all parts of the world.{{sfn|Woodward|1911|pp=367–368}}

Familiar then with recent glaciation, Agassiz and the English geologist William Buckland visited the mountains of Scotland in 1840. There, they found clear evidence in different locations of glacial action. The discovery was announced to the Geological Society of London in successive communications. The mountainous districts of England, [[Wales]], and [[Ireland]] were understood to have been centres for the dispersion of glacial debris. Agassiz remarked "that great sheets of ice, resembling those now existing in [[Greenland]], once covered all the countries in which unstratified gravel (boulder drift) is found; that this gravel was in general produced by the [[trituration]] of the sheets of ice upon the subjacent surface, etc."{{sfn|Woodward|1911|p=368}}
[[File:SAM PC 0 - Ice auger of Louis Agassiz and Eduard Desor.jpg|thumb|upright=0.4|The man-sized iron [[auger (drill)|auger]] that was used by Agassiz to drill up to 7.5 m deep into the [[Unteraar Glacier]] to take its temperature ([[Swiss Alpine Museum]], Bern)]]

In his later years, Agassiz applied his glacial theories to the geology of the Brazilian tropics, including the Amazon. Agassiz began with a working hypothesis which could be tested by the results of fieldwork to find either inconclusive, or conclusively supporting or refuting evidence. A hypothesis that can be conclusively refuted is better than a hypothesis that is difficult to test. Agassiz had a close association with his student and field assistant, the geologist [[Charles Frederick Hartt|Charles Hartt]] who eventually refuted Agassiz's theories about the Amazon based on his fieldwork there. Instead of evidence for any glacial processes, he found chemically weathered sediments from marine and tropical fluvial, not glacial, processes, a finding that later geologists confirmed.<ref>Brice, W. R. and Silvia F. de M. Figueiroa 2001 Charles Hartt, Louis Agassiz, and the controversy over Pleistocene glaciation in Brazil. History of Science 39(2): 161–184.
</ref> Agassiz hypothesis that the Amazon was affected by the [[Last Glacial Maximum]] was correct, although the mechanism causing the effect was non-glacial. The Amazon rainforest was split into two large blocks by extensive savanna during the LGM.

==United States==
With the aid of a grant of money from the [[king of Prussia]], Agassiz crossed the [[Atlantic]] in the autumn of 1846 to investigate the natural history and geology of North America and to deliver a course of lectures on "The Plan of Creation as shown in the Animal Kingdom"<ref>Smith, p.&nbsp;52.</ref> by invitation from [[John Amory Lowell]], at the [[Lowell Institute]] in [[Boston]], [[Massachusetts]]. The financial offers that were presented to him in the [[United States]] induced him to settle there, where he remained to the end of his life.{{sfn|Woodward|1911|p=368}} He was elected a foreign honorary member of the [[American Academy of Arts and Sciences]] in 1846.<ref name=AAAS>{{cite web|title=Book of Members, 1780–2010: Chapter A|url=http://www.amacad.org/publications/BookofMembers/ChapterA.pdf|publisher=American Academy of Arts and Sciences|access-date=April 6, 2011}}</ref>

In 1846, still married to Cecilie, who remained with their three children in Switzerland, Agassiz met [[Elizabeth Cabot Agassiz|Elizabeth Cabot Cary]] at a dinner. The two developed a romantic attachment, and when his wife died in 1848, they made plans to marry. The ceremony took place on April 25, 1850, in Boston, Massachusetts at [[King's Chapel]]. Agassiz brought his children to live with them, and Elizabeth raised and developed close relationships with her step-children. She had no children of her own.<ref name="Paton">Paton, Lucy Allen. ''Elizabeth Cabot Agassiz; a biography.'' Boston, Houghton Mifflin Company, 1919.</ref>

Agassiz had a mostly cordial relationship with the Harvard botanist [[Asa Gray]] despite their disagreements.<ref>{{cite book|last=Dupree|first=A. Hunter|year=1988|title=Asa Gray, American Botanist, Friend of Darwin|publisher=Johns Hopkins University Press|location=Baltimore, MD|isbn=978-0-801-83741-8|pages=152–154, 224–225}}</ref> Agassiz believed each human race had been separately created,<ref>See, for instance, [https://archive.org/details/sim_christian-examiner_1851-01_50_1 Agassiz, Louis (1851), "Contemplations of God in the Kosmos", ''The Christian Examiner and Religious Miscellany'', Vol. 50, No. 1, (January 1851), pp. 1–17.]</ref> but Gray, a supporter of [[Charles Darwin]], believed in the shared evolutionary ancestry of all humans.<ref name="dupree">{{cite book|last=Dupree|first=A. Hunter|year=1988|title=Asa Gray, American Botanist, Friend of Darwin|publisher=Johns Hopkins University Press|location=Baltimore, MD|isbn=978-0-801-83741-8|pages=ix–xv, 152–154, 224–225}}</ref> In addition, Agassiz was a member of the [[Scientific Lazzaroni]], a group of mostly physical scientists who wanted American academia to mimic the more autocratic academic structures of European universities, but Gray was a staunch opponent of that group.

Agassiz's engagement for the [[Lowell Institute]] lectures precipitated the establishment in 1847 of the [[Lawrence Scientific School]] at Harvard University, with Agassiz as its head.<ref>Smith (1898), pp. 39–41.</ref> Harvard appointed him professor of zoology and geology, and he founded the [[Museum of Comparative Zoology]] there in 1859 and served as its first director until his death in 1873. During his tenure at Harvard, Agassiz studied the effect of the last ice age in North America.{{citation needed|date=May 2018}} In August 1857, Agassiz was offered the chair of palaeontology in the [[Museum of Natural History, Paris]], which he refused. He was later decorated with the [[Cross of the Legion of Honor]].<ref name="BDA1906p63">{{harvnb|Johnson|1906|p=63}}</ref>

Agassiz continued his lectures for the Lowell Institute. In succeeding years, he gave lectures on "Ichthyology" (1847–1848), "Comparative Embryology" (1848–1849), "Functions of Life in Lower Animals" (1850–1851), "Natural History" (1853–1854), "Methods of Study in Natural History" (1861–1862), "Glaciers and the Ice Period" (1864–1865), "Brazil" (1866–1867), and "Deep Sea [[Marine biology dredge|Dredging]]" (1869–1870).<ref>Smith (1898), pp. 52–66.</ref> In 1850, he had married Elizabeth Cabot Cary, who later wrote introductory books about natural history and a lengthy biography of her husband after he had died.<ref>{{Cite book|url=http://archive.org/details/louisagassizhisl02agas|title=Louis Agassiz; his life and correspondence|last=Agassiz|first=Elizabeth Cabot Cary|date=1893|publisher=Boston and New York, Houghton, Mifflin and company|others=MBLWHOI Library}}</ref>

Agassiz served as a nonresident lecturer at [[Cornell University]] while he was also on faculty at Harvard.<ref>''A History of Cornell'' by Morris Bishop (1962), p. 83.</ref> In 1852, he accepted a medical professorship of [[comparative anatomy]] at [[Charlestown, Massachusetts]], but he resigned in two years.{{sfn|Woodward|1911|p=368}} From then on, Agassiz's scientific studies dropped off, but he became one of the best-known scientists in the world. By 1857, Agassiz was so well-loved that his friend [[Henry Wadsworth Longfellow]] wrote "The Fiftieth Birthday of Agassiz" in his honor and read it at a dinner given for Agassiz by the [[Saturday Club (Boston, Massachusetts)|Saturday Club]] in [[Cambridge, Massachusetts|Cambridge]].{{sfn|Woodward|1911|p=368}} Agassiz's own writing continued with four (of a planned 10) volumes of ''Natural History of the United States'', published from 1857 to 1862. He also published a catalog of papers in his field, ''Bibliographia Zoologiae et Geologiae'', in four volumes between 1848 and 1854.<ref>{{Cite book |last=Agassiz |first=Louis |title=Bibliographia Zoologiæ Et Geologiæ. A General Catalogue of All Books, Tracts, and Memoirs on Zoology and Geology |volume= 1 |publisher=Ray Society |year=1848 |isbn=}}</ref><ref>{{Cite book |last=Agassiz |first=Louis |title=Bibliographia Zoologiæ Et Geologiæ A General Catalogue of All Books, Tracts, and Memoirs On Zoology and Geology|volume =2 |publisher=Ray Society |year=1850 |isbn=}}</ref><ref>{{Cite book |last=Agassiz |first=Louis |title=Bibliographia Zoologiæ Et Geologiæ A General Catalogue of All Books, Tracts, and Memoirs On Zoology and Geology|volume =3 |publisher=Ray Society |year=1853 |isbn=}}</ref><ref>{{Cite book |last=Agassiz |first=Louis |title=Bibliographia Zoologiæ Et Geologiæ A General Catalogue of All Books, Tracts, and Memoirs on Zoology and Geology|volume= 4 |publisher=Ray Society |year=1854}}</ref>

Stricken by ill health in the 1860s, Agassiz resolved to return to the field for relaxation and to resume his studies of Brazilian fish. In April 1865, he led the [[Thayer Expedition]] to Brazil. While there, he commissioned two photographers, [[Augusto Stahl]] and [[Georges Leuzinger]], to accompany the expedition and produce somatological images of Indigenous people and enslaved Africans and Black people.<ref>{{Cite book |last=Ermakoff|first=George|title=O negro na fotografia brasileira do século XIX |publisher=G. Ermakoff |year=2004}}</ref> After his return in August 1866, an account of the expedition, ''A Journey in Brazil'',<ref>{{Cite book |last=Agassiz |first=Louis |title=A Journey in Brazil |publisher=Ticknor and Fields |year=1868 |isbn=9780608433790}}</ref> was published in 1868. In December 1871, he made a second eight-month excursion, known as the ''[[Hassler (vessel)|Hassler]]'' expedition under the command of Commander [[Philip C. Johnson Jr.|Philip Carrigan Johnson]] (the brother of [[Eastman Johnson]]) and visited South America on its southern Atlantic and Pacific Seaboards. The ship explored the [[Magellan Strait]], which drew the praise of [[Charles Darwin]].<ref>{{Cite web |title=Scientific results of a Journey in Brazil: Geology and Physical Georgraphy of Brazil by Jean Louis Rodolphe Agassiz (1807–1873) and Fred Hart – 1870 |url=https://www.biblio.com/book/scientifc-results-journey-brazil-geology-physical/d/54684666}}</ref>

Following the establishment of the first U.S. [[American Society for the Prevention of Cruelty to Animals|Society for the Prevention of Cruelty to Animals]] in New York City in 1866, Agassiz was called on to help settle disputes about animal behavior. He deemed the way turtles were shipped caused them suffering, while [[P.T. Barnum]] argued with Agassiz' support that his snakes would eat only live animals.<ref>{{cite book | first =Ernest | last = Freeberg | title = A Traitor to his Species: Henry Bergh and the Birth of the Animal Rights Movement | location =New York | publisher =Basic Books | date = 2020 | pages = 17–18, 65–66 }}</ref>

His second wife, [[Elizabeth Cary Agassiz]], assisted him in preparing his ''A Journey in Brazil''. Along with her stepson, [[Alexander Agassiz]], she wrote ''Seaside Studies in Natural History'' and ''Marine Animals of Massachusetts''.<ref name="BDA1906p63" /> Elizabeth wrote at the Strait that "the ''Hassler'' pursued her course, past a seemingly endless panorama of mountains and forests rising into the pale regions of snow and ice, where lay glaciers in which every rift and crevasse, as well as the many cascades flowing down to join the waters beneath, could be counted as she steamed by them.... These were weeks of exquisite delight to Agassiz. The vessel often skirted the shore so closely that its geology could be studied from the deck."<ref>{{Cite book |last=Agassiz |first=Louis |title=Louis Agassiz His Life and Correspondence |publisher=Houghton, Mifflin and Company |year=1885 |page=719}}</ref>

==Family==
[[File:Agassiz Louis 1807-1873.png|thumb|left|upright|Agassiz in middle age]]
From his first marriage to Cecilie Braun, Agassiz had two daughters, Ida and [[Pauline Agassiz Shaw|Pauline]], and a son, [[Alexander Agassiz|Alexander]].<ref>{{cite book |last=Irmscher |first=Christoph |title=Louis Agassiz: Creator of American Science |url=https://archive.org/details/louisagassiz00chri |url-access=registration |year=2013 |publisher=Houghton Mifflin Harcourt|isbn=9780547577678 }}</ref>
In 1863, Agassiz's daughter Ida married [[Henry Lee Higginson]], who later founded the [[Boston Symphony Orchestra]] and was a benefactor to Harvard and other schools. On November 30, 1860, Agassiz's daughter [[Pauline Agassiz Shaw|Pauline]] was married to [[Quincy Adams Shaw]] (1825–1908), a wealthy Boston merchant and later a benefactor to the Boston [[Museum of Fine Arts, Boston|Museum of Fine Arts]].<ref>{{Cite book |title=Quincy Adams Shaw Collection | author1=Museum of Fine Arts |year=1918 |publisher=Museum of Fine Arts |location=Boston, Massachusetts |page=2 |url=https://archive.org/details/quincyadamsshawc00muse}}</ref> Pauline Agassiz Shaw later became a prominent educator, suffragist, and philanthropist.<ref>{{Cite web|title=Pauline Agassiz Shaw|url=https://bwht.org/pauline-agassiz-shaw/|access-date=2020-10-25|website=bwht.org}}</ref>

==Later life==
In the last years of his life, Agassiz worked to establish a permanent school in which zoological science could be pursued amid the living subjects of its study. In 1873, the private philanthropist John Anderson gave Agassiz the island of [[Penikese]], in [[Buzzards Bay (bay)|Buzzards Bay]], Massachusetts (south of [[New Bedford, Massachusetts|New Bedford]]), and presented him with $50,000 to endow it permanently as a practical school of natural science that would be especially devoted to the study of marine zoology.{{sfn|Woodward|1911|p=368}} The school collapsed soon after Agassiz's death but is considered to be a precursor of the nearby Woods Hole [[Marine Biological Laboratory]].<ref>{{Cite book|title=Oceanography: The Past|last=Dexter|first=R.W.|publisher=Springer|year=1980|isbn=978-1-4613-8090-0|editor-last=Sears|editor-first=Mary|location=New York|pages=94–100|chapter=The Annisquam Sea-side Laboratory of Alpheus Hyatt, Predecessor of the Marine Biological Laboratory at Woods Hole, 1880–1886|doi=10.1007/978-1-4613-8090-0_10|oclc=840282810|editor-last2=Merriman|editor-first2=Daniel}}</ref>

Agassiz had a profound influence on the American branches of his two fields and taught many future scientists who would go on to prominence, including [[Alpheus Hyatt]], [[David Starr Jordan]], [[Joel Asaph Allen]], [[Joseph Le Conte]], [[Ernest Ingersoll]], [[William James]], [[Charles Sanders Peirce]], [[Nathaniel Shaler]], [[Samuel Hubbard Scudder]], [[Alpheus Packard]], and his son [[Alexander Emanuel Agassiz]]. He had a profound impact on the paleontologist [[Charles Doolittle Walcott]] and the natural scientist [[Edward S. Morse]]. Agassiz had a reputation for being a demanding teacher. He would allegedly "lock a student up in a room full of turtle-shells, or lobster-shells, or oyster-shells, without a book or a word to help him, and not let him out till he had discovered all the truths which the objects contained."<ref name=James>James, William.  "Louis Agassiz, Words Spoken.... at the Reception of the American Society of Naturalists.... [Dec 30, 1896].  pp. 9–10. Cambridge, 1897. Quoted in Cooper 1917, pp. 61–62.</ref> Two of Agassiz's most prominent students detailed their personal experiences under his tutelage: Scudder, in a short magazine article for'' [[Every Saturday]]'',<ref name=Scudder>{{cite book |last1=Erlandson |first1=David A. |display-authors=etal |url=https://books.google.com/books?id=mOawndGmMsIC&pg=PA1 |title=Doing Naturalistic Inquiry: A Guide to Methods |publisher=Sage Publications |year=1993 |pages=1–4|isbn=978-0-8039-4938-6}}; Originally published in {{cite journal |last=Scudder |first=Samuel H. |title=Look at your fish |journal=Every Saturday |date=April 4, 1874 |volume=16 |pages=369–370}}</ref> and [[Nathaniel Shaler|Shaler]], in his ''Autobiography''.<ref name=Shaler>{{cite book |last1=Shaler |first1=Nathaniel |last2=Shaler |first2=Sophia Penn Page | title=The Autobiography of Nathaniel Southgate Shaler with a Supplementary Memoir by his Wife | publisher=Houghton Mifflin Company | year=1909 | location=Boston | pages=[https://archive.org/details/cu31924012131698/page/n121 92]–99 | url=https://archive.org/details/cu31924012131698}}</ref> Those and other recollections were collected and published by Lane Cooper in 1917,<ref name=Cooper>{{cite book |last=Cooper |first=Lane | title=Louis Agassiz as a Teacher: Illustrative Extracts on his Method of Instruction | publisher=The Comstock Publishing Company | year=1917 | location=Ithaca | url=https://archive.org/details/louisagassizaste1917coop}}</ref> which Ezra Pound would draw on for his anecdote of [[Parable of the sunfish|Agassiz and the sunfish]].<ref name=Pound>{{cite book |last=Pound |first=Ezra | title=ABC of Reading | publisher=New Directions | year=2010 | location=New York | pages=17–18 | isbn=978-0-8112-1893-1 | url=https://books.google.com/books?id=0GazhoHAYQgC}}</ref>

In the early 1840s, Agassiz named two fossil fish species after [[Mary Anning]] (''[[Acrodus anningiae]]'' and ''Belenostomus anningiae'') and another after her friend, [[Elizabeth Philpot]]. Anning was a paleontologist known around the world for important finds, but because of her gender, she was often not formally recognized for her work. Agassiz was grateful for the help that the women gave him in examining fossil fish specimens during his visit to [[Lyme Regis]] in 1834.<ref name="Emling169">{{Harvnb|Emling|2009|pp=169–170}}</ref>

Agassiz died in [[Cambridge, Massachusetts]], in 1873 and was buried on the Bellwort Path at [[Mount Auburn Cemetery]],<ref name="BDA1906p64">{{harvnb|Johnson|1906|p=64}}</ref> joined later by his wife. His monument is a boulder from a [[Aargletschers|glacial moraine of the Aar]] near the site of the old {{ill|Hôtel des Neuchâtelois|nl|Hôtel des Neuchâtelois}}, not far from the spot where his hut once stood. His grave is sheltered by pine trees from his old home in Switzerland.{{sfn|Woodward|1911|p=368}}

==Legacy==
The Cambridge elementary school north of Harvard University was named in his honor, and the surrounding neighborhood became known as "[[Agassiz, Cambridge, Massachusetts|Agassiz]]" as a result. The school's name was changed to the Maria L. Baldwin School on May 21, 2002, because of concerns about Agassiz's involvement in scientific racism and to honor [[Maria Louise Baldwin]], the African-American principal of the school, who served from 1889 to 1922.<ref>{{cite web |url=http://www.peaceworkmagazine.org/pwork/0204/020420.htm |title=Peacework Back Issues &#124; the Mismeasure of Maria Baldwin |website=www.peaceworkmagazine.org |access-date=22 May 2022 |archive-url=https://web.archive.org/web/20071023054813/http://www.peaceworkmagazine.org/pwork/0204/020420.htm |archive-date=23 October 2007 |url-status=dead}}</ref><ref name="thecrimson2002">{{Cite web|url=https://www.thecrimson.com/article/2002/5/22/committee-renames-local-agassiz-school-the/|title=Committee Renames Local Agassiz School &#124; News &#124; The Harvard Crimson|website=www.thecrimson.com}}</ref> The neighborhood, however, continued to be known as Agassiz.<ref>{{cite web|url=http://www.cambridgema.gov/~CDD/cp/neigh/8/agassiz_ns_3.pdf |title=agassiz_ns_3.pdf |access-date=October 3, 2005 |url-status=unfit |archive-url=https://web.archive.org/web/20100607045807/http://www.cambridgema.gov/~CDD/cp/neigh/8/agassiz_ns_3.pdf |archive-date=June 7, 2010 }}. cambridgema.gov</ref> {{Circa|2009}}, neighborhood residents decided to rename the neighborhood's community council as the "Agassiz-Baldwin Community".<ref>Meghan E. Irons. "Hurdles Cleared, Cambridge Group Celebrates Arts Project." ''Boston Globe'', October 1, 2009, p. B5.</ref> Then, in July 2021, culminating a two-year effort on the part of neighborhood residents, the Cambridge City Council voted unanimously to change the name to the Baldwin Neighborhood.<ref>Marc Levy. "Baldwin Neighborhood Name is Approved 9–0, Replacing Agassiz; Second Such Change Since '15." ''Cambridge (Massachusetts) Day'', August 2, 2021, [https://www.cambridgeday.com/2021/08/02/baldwin-neighborhood-name-is-approved-9-0-replacing-agassiz-second-such-change-since-15/]</ref>  An elementary school, the Agassiz Elementary School in [[Minneapolis, Minnesota]], existed from 1922 to 1981.<ref>{{cite web|url=http://mpshistory.mpls.k12.mn.us/agassiz|title=Agassiz|website=mpshistory.mpls.k12.mn.us|access-date=July 6, 2017}}</ref>

===Geological tributes===
[[File:Agassiz.main.sk.jpg|thumb|upright|Agassiz's grave, Mount Auburn Cemetery, Cambridge, Massachusetts, is a boulder from the moraine of the Aar Glaciers, near where he once lived.]]
An ancient [[glacial lake]] that formed in central North America, [[Lake Agassiz]], is named after him, as are [[Mount Agassiz (California)|Mount Agassiz]] in [[Palisades (California Sierra)|California's Palisades]], [[Mount Agassiz (Utah)|Mount Agassiz]] in the [[Uinta Mountains]] of Utah, [[Agassiz Peak]] in Arizona, [[Agassiz Rock]] in Massachusetts, and the [[Agassizhorn]] in the Bernese Alps in his native Switzerland. [[Agassiz Glacier (Montana)|Agassiz Glacier]] in Montana, Agassiz Creek in [[Glacier National Park (U.S.)|Glacier National Park]], [[Agassiz Glacier (Alaska)|Agassiz Glacier]] in the [[Saint Elias Mountains]] of Alaska, and [[Mount Agassiz (New Hampshire)|Mount Agassiz]] in the [[White Mountains (New Hampshire)|White Mountains]] of New Hampshire also bear his name.  A [[impact crater|crater]] on [[Mars]], ''[[Crater Agassiz]]'',<ref>{{cite book | last1=Schmadel | first=Lutz D. | title=Dictionary of Minor Planet Names | publisher=Springer Science & Business Media | year=2012 | isbn=978-3-642-29718-2 | page=176 | url=https://books.google.com/books?id=VoJ5nUyIzCsC}}</ref> and a promontorium on the moon are also named in his honor. [[Cape Agassiz]], a headland situated in [[Palmer Land]], [[Antarctica]], is named in his honor. A [[Asteroid belt|main-belt]] [[asteroid]], [[2267 Agassiz]], is also named in association with him.

===Biological tributes===
Several animal species are named in honor of him, including 
*Agassiz's dwarf cichlid ''[[Apistogramma agassizii]]'' {{small|[[Franz Steindachner|Steindachner]], 1875}};
*Agassiz's perchlet, also known as Agassiz's glass fish; and the olive perchlet ''[[Ambassis agassizii]]'' {{small|[[Franz Steindachner|Steindachner]], 1866}}; 
*The Spring Cavefish ''[[Forbesichthys agassizii]]'' {{small|([[Frederic Ward Putnam|Putnam]], 1872)}}; 
*the catfish ''[[Corydoras agassizii]]'' {{small|[[Franz Steindachner|Steindachner]], 1876}}; 
*the Rio Skate ''[[Rioraja agassizii]]'' {{small|([[Johannes Peter Müller|J. P. Müller]] & [[Friedrich Gustav Jakob Henle|Henle]], 1841)}};
*The South American fish ''[[Leporinus agassizii]]'' <ref name = ETYFish>{{cite web | url = http://www.etyfish.org/characiformes2/ | title = Order CHARACIFORMES: Families TARUMANIIDAE, ERYTHRINIDAE, PARODONTIDAE, CYNODONTIDAE, SERRASALMIDAE, HEMIODONTIDAE, ANOSTOMIDAE and CHILODONTIDAE | access-date = 24 March 2022 | author1 = Christopher Scharpf | author2 = Kenneth J. Lazara | name-list-style = amp | work = The ETYFish Project Fish Name Etymology Database | publisher = Christopher Scharpf and Kenneth J. Lazara | date = 22 September 2018 | archive-date = January 9, 2022 | archive-url = https://web.archive.org/web/20220109173908/https://etyfish.org/characiformes2/ | url-status = dead }}</ref>
*the Snailfish ''[[Liparis agassizii]]'' {{small|[[Frederic Ward Putnam|Putnam]], 1874}}; 
*a sea snail, ''[[Borsonella agassizii]]'' {{small|([[William Healey Dall|Dall]], 1908)}}; 
*a species of crab ''[[Eucratodes agassizii]]'' {{small|[[Alphonse Milne-Edwards|A. Milne Edwards]], 1880}};
*''[[Capniidae|Isocapnia agassizi]]'' {{small|Ricker, 1943}} (a [[stonefly]]); 
*''[[Publius agassizi]]'' {{small|([[Johann Jakob Kaup|Kaup]], 1871)}} (a [[Passalidae|passalid beetle]]);
*''[[Xylocrius agassizi]]'' {{small|([[John Lawrence LeConte|LeConte]], 1861)}} (a [[longhorn beetle]]);
*''[[Exoprosopa agassizii]]'' {{small|Loew, 1869}} (a [[Bombyliidae|bee fly]]);
*''[[Chelonia agassizii]]'' {{small|[[Marie Firmin Bocourt|Bocourt]], 1868}} (Galápagos green turtle);<ref name=EDR>Beolens, Bo; Watkins, Michael; Grayson, Michael (2011). ''The Eponym Dictionary of Reptiles''. Baltimore: Johns Hopkins University Press. xiii + 296 pp. {{ISBN|978-1-4214-0135-5}}. ("Agassiz, J.L.R.", p. 2).</ref> 
*''[[Philodryas|Philodryas agassizii]]'' {{small|([[Giorgio Jan|Jan]], 1863)}} (a South American snake);<ref name=EDR/> 
and the most well-known, 
*''[[Gopherus agassizii]]'' {{small|([[James Graham Cooper|Cooper]], 1863)}} (the desert tortoise).<ref name=EDR/> 
*In 2020, a new genus of pycnodont fish (Actinopterygii, Pycnodontiformes) named ''[[Agassazilia erfoundina]]'' (Cooper and Martill, 2020) from the Moroccan Kem Kem Group was named in honor of Agassiz, who first identified the group in the 1830s.

===Tribute awards===
In 2005, the [[European Geosciences Union]] Division on Cryospheric Sciences established the Louis Agassiz Medal, awarded to individuals in recognition of their outstanding scientific contribution to the study of the [[cryosphere]] on Earth or elsewhere in the [[Solar System]].<ref>{{cite web | url=http://www.egu.eu/awards-medals/louis-agassiz/ | title=Louis Agassiz Medal | publisher=European Geosciences Union | year=2005 | access-date=February 8, 2015}}</ref>

Agassiz took part in a monthly gathering called the [[Saturday Club (Boston, Massachusetts)|Saturday Club]] at the [[Omni Parker House|Parker House]], a meeting of Boston writers and intellectuals. He was therefore mentioned in a stanza of the [[Oliver Wendell Holmes Sr.]] poem "[[s:At the Saturday Club|At the Saturday Club]]:"

{{poemquote|
There, at the table's further end I see
In his old place our Poet's vis-à-vis,
The great PROFESSOR, strong, broad-shouldered, square,
In life's rich noontide, joyous, debonair
...

How will her realm be darkened, losing thee,
Her darling, whom we call our AGASSIZ!}}

=== Daguerreotypes of Renty and Delia Taylor ===
[[File:Renty an African slave.jpg|right|thumb|200px|Renty Taylor]]
In 1850, Agassiz commissioned [[daguerreotypes]], which were described as "haunting and voyeuristic" of the enslaved [[Renty Taylor]] and Taylor's daughter, Delia, to further his arguments about black inferiority.<ref name=":0" /> They are the earliest known photographs of enslaved persons.<ref name="The Day 2019">{{cite web |last1=Moser |first1=Erica |title=Descendants of racist scientist back Norwich woman in fight over slave images |url=https://www.theday.com/local-news/20190620/descendants-of-racist-scientist-back-norwich-woman-in-fight-over-slave-images |website=theday.com |publisher=The Day |access-date=21 June 2019}}</ref><ref>{{cite web |last1=Browning |first1=Kellen |title=Descendants of slave, white supremacist join forces on Harvard's campus to demand school hand over 'family photos' |url=https://www.bostonglobe.com/metro/2019/06/20/descendants-slave-white-supremacist-join-forces-harvard-campus-demand-school-hand-over-family-photos/62v7Z5dztzml0yep7SuosI/story.html |website=www.bostonglobe.com |publisher=The Boston Globe |access-date=21 June 2019}}</ref><ref name=":0">{{cite news|date=March 20, 2019|title=Who Should Own Photos of Slaves? The Descendants, not Harvard, a Lawsuit Says|language=en|work=The New York Times|url=https://www.nytimes.com/2019/03/20/us/slave-photographs-harvard.html|access-date=March 29, 2019}}</ref><ref>{{cite news|title=The World Is Watching: Woman Suing Harvard for Photos of Enslaved Ancestors Says History Is At Stake|url=https://www.democracynow.org/2019/3/29/the_world_is_watching_woman_suing|access-date=March 29, 2019|work=[[Democracy Now!]]|date=March 29, 2019|language=en}}</ref> Agassiz left the images to Harvard, and they remained in the Peabody Museum's attic until 1976, when they were rediscovered by Ellie Reichlin, a former staff member.<ref>{{Cite news|last=Sehgal|first=Parul|date=2020-10-02|title=The First Photos of Enslaved People Raise Many Questions About the Ethics of Viewing|language=en-US|work=The New York Times|url=https://www.nytimes.com/2020/09/29/books/to-make-their-own-way-in-world-zealy-daguerreotypes.html|access-date=2020-10-05|issn=0362-4331}}</ref><ref name=":1">{{Cite web|date=June 1977|title=Faces of Slavery: A Historical Find|url=https://www.americanheritage.com/faces-slavery-historical-find|access-date=2020-10-05|website=American Heritage magazine}}</ref> The 15 daguerrotypes were in a case with the embossing "J. T. Zealy, Photographer, Columbia," with several handwritten labels, which helped in later identification.<ref name=":1" /> Reichlin spent months doing research to try to identify the people in the photos, but Harvard University did not make efforts to contact the families and licensed the photos for use.<ref name=":1" /><ref name=":2">{{Cite web|date=March 22, 2019|title=Woman who claims descent sues Harvard over refusal to return photos of enslaved man from 1850|url=http://www.stlamerican.com/news/local_news/woman-who-claims-descent-sues-harvard-over-refusal-to-return-photos-of-enslaved-man-from/article_aac910c0-4cbf-11e9-826f-bb433eadf065.html|access-date=2020-10-05|website=St. Louis American|language=en}}</ref>

In 2011, Tamara Lanier wrote a letter to the president of Harvard that identified herself as a direct descendant of the Taylors and asked the university to turn over the photos to her.<ref name=":2" /><ref>{{Cite web|date=2019-03-20|title=Harvard 'Shamelessly' Profits From Photos Of Slaves, Lawsuit Claims|url=https://boston.cbslocal.com/2019/03/20/harvard-university-slave-photos-lawsuit-tamara-lanier/|access-date=2020-10-05|language=en-US}}</ref>

In 2019, Taylor's descendants sued Harvard for the return of the images and unspecified damages.<ref>{{cite web |last1=Tony Marco |first1=Ray Sanchez and |title=The descendants of slaves want Harvard to stop using iconic photos of their relatives |url=https://www.cnn.com/2019/03/20/us/harvard-lawsuit-slave-photos/index.html |website=/www.cnn.com |date=March 20, 2019 |publisher=CNN |access-date=21 June 2019}}</ref> The lawsuit was supported by 43 living descendants of Agassiz, who wrote in a letter of support, "For Harvard to give the daguerreotypes to Ms. Lanier and her family would begin to make amends for its use of the photos as exhibits for the white supremacist theory Agassiz espoused." Everyone must evaluate fully "his role in promoting a pseudoscientific justification for white supremacy."<ref name="The Day 2019" />
Settlement of the lawsuit was announced in May 2025.  All of the Agassiz-Zealy daguerrotypes are expected to be transferred to a museum of African-American history in South Carolina (none go to Ms. Lanier personally), and Harvard is to pay an undisclosed monetary sum to Ms. Lanier for her emotional distress.<ref>{{cite news |last1=McGrady |first1=Clyde |title=Harvard Relents After Protracted Fight Over Slave Photos |url=https://www.nytimes.com |access-date=30 May 2025 |work=New York Times |date=May 28, 2025}}</ref>

Aggasiz-Zeally Gallery
<gallery>
File:Renty an African slave.jpg| "Papa" [[Renty Taylor]] Born Congo, 1775-died on/after 1866. Field hand on B.F. Taylor Plantation, Columbia South Carolina [Note a side profile picture can be found at online article "Louis Agassiz Two Faces"]
File:Delia1850FrontPortrait.jpg|Delia (Born America); daughter of Renty on B.F. Taylor Plantation, Columbia South Carolina [Picture # 1]
File:Slave Portrait Agassiz Zealy Woman Side Bust 2.jpg|Delia daughter of Renty on B.F. Taylor Plantation, Columbia South Carolina [Picture # 2]
<!--  -->
File:JackGuineaProfileSlavePortrait.jpg|Jack of Guinea, a slave driver  on B.F. Taylor Plantation, Columbia South Carolina [Picture # 1]
File:Jack1850FrontZealy.jpg|Jack of Guinea, a slave driver  on B.F. Taylor Plantation, Columbia South Carolina [Picture # 2]
File:Drana (frontal portrait).jpg|Drana daughter of Jack on B.F. Taylor Plantation, Columbia South Carolina [Picture # 1]
File:Drana (profile view).jpg|Drana daughter of Jack on B.F. Taylor Plantation, Columbia South Carolina [Picture # 2]
<!--  -->
File:Slave Portrait Agassiz Zealy Man Side Bust 2.jpg|Fassena a mandingo Carpender on Wade Hampton Plantation, South Carolina[Note a full face picture can be found at https://saa3dm.org/2021/11/16/1850]
File:Slave Portrait Agassiz Zealy Man Standing Back.jpg| "Jem. A Gullah..B.W. Green Plantation [See American Heritage June 1977 "Faces of Slavery"]
File:Slave Portrait Agassiz Zealy Man Front 01.jpg|
File:Slave Portrait Agassiz Zealy Man Side One Leg.jpg|
</gallery>

==Polygenism and racism==
[[File:Agassiz in the Concrete.jpg|thumb|left|After the [[1906 San Francisco earthquake|1906 San Francisco earth{{shy}}quake]] toppled [[Louis Agassiz (sculpture)|Agassiz's statue]] from the façade of [[Stanford]]'s zoology building, Stanford President [[David Starr Jordan]] wrote, "Somebody{{mdashb}}[[Frank Angell|Dr. Angell]], perhaps{{mdashb}}remarked that 'Agassiz was great in the abstract but not in the concrete.{{'"}}<ref>{{cite web | url=http://quake06.stanford.edu/centennial/tour/stop3.html | title=Earthquake impacts on prestige | work=Stanford University and the 1906 earthquake | publisher=Stanford University | access-date=June 22, 2012}}</ref>]]

Agassiz was a well-known natural scientist of his generation in America.<ref>{{Cite journal |last1=Smith |first1=David C. |last2=Borns |first2=Harold W. |date=2000 |title=Louis Agassiz, the Great Deluge, and Early Maine Geology |url=https://www.jstor.org/stable/3858648 |journal=Northeastern Naturalist |volume=7 |issue=2 |pages=157–177 |doi=10.2307/3858648 |jstor=3858648 |issn=1092-6194|url-access=subscription }}</ref> In addition to being a natural scientist, Agassiz wrote prolifically in the field of scientific [[polygenism]] after he came to the United States.

Upon arriving in Boston in 1846, Agassiz spent a few months acquainting himself with the northeast region of the United States.<ref name=":12">{{Cite book |author=Lurie, Edward |url=http://worldcat.org/oclc/18049437 |title=Louis Agassiz, a life in science |date=1988 |publisher=Johns Hopkins University Press |isbn=0-8018-3743-X |oclc=18049437}}</ref> He spent much of his time with [[Samuel George Morton]], a famous American anthropologist at the time who became well known by analyzing fossils brought back by Lewis and Clark.<ref name=":02">{{Cite journal |last=Menand |first=Louis |date=2001 |title=Morton, Agassiz, and the Origins of Scientific Racism in the United States |url=https://doi.org/10.2307/3134139 |journal=[[The Journal of Blacks in Higher Education]] |issue=34 |pages=110–113 |doi=10.2307/3134139 |jstor=3134139 |url-access=subscription }}</ref> One of Morton’s personal projects involved studying cranial capacity of human skulls from around the world. Morton aimed to use [[craniometry]] to prove that white people were biologically superior to other races. His work "''Crania Aegyptiaca"'' claimed to support the polygenism belief that the races were created separately and each had their own unique attributes.<ref>{{Cite book |author=Morton, Samuel George |url=http://worldcat.org/oclc/713232597 |title=Catalogue of skulls of man and the inferior animals : in the collection of Samuel George Morton, M.D., Penn. and Edinb. Vice President of the Academy of Natural Sciences of Philadelphia. Author of "Crania Americana," "Crania Aegyptiaca," etc. |date=1849 |publisher=Merrihew & Thompson, printers, No. 7 Carter's Alley |oclc=713232597}}</ref>

Morton relied on other scientists to send him skulls along with information about where they were acquired. Factors that can affect cranial capacity, such as body size and gender, were not taken into consideration by Morton.<ref name=":02" /> He made questionable judgment calls such as dismissing Hindu skull calculations from his Caucasian cranial measurements because they brought the overall average down. Oppositely, he included Peruvian skull measurements alongside Native American calculations even though the Peruvian numbers lowered the average score. Despite Morton's unsound methods, his published work on cranial capacities across races was deemed authoritative in the United States and Europe. Morton is a primary influence on Agassiz's belief in polygenism.<ref name=":02" />

[[John Amory Lowell]] invited Agassiz to present twelve lectures in December 1846 on three subjects titled "''The Plan of Creation as shown in the Animal Kingdom'', ''Ichthyology,'' and ''Comparative Embryology"'' as a part of the Lowell Lecture series. These lectures were widely attended with up to 5,000 people in attendance on some nights.<ref>{{Cite web |last1=University |first1=© Stanford |last2=Stanford |last3=California |date=2019-11-23 |title=Jean Louis Rodolphe Agassiz |url=https://exhibits.stanford.edu/seaside/feature/jean-louis-rodolphe-agassiz |access-date=2023-02-24 |website=Hopkins Seaside Laboratory (1892–1917) – Spotlight at Stanford |language=en}}</ref> It was during these lectures that Agassiz announced for the first time that black and white people had different origins but were part of the same species.<ref name=":02" /> Agassiz repeated this lecture 10 months later to the Charleston Literary Club but changed his original stance, claiming that black people were physiologically and anatomically a distinct species.<ref name=":02" />

Agassiz believed that humans did not descend from one single common ancestor. He believed that like plants and animals, various regions have differentiated species of humans'''.<ref name=":12" />''' He considered this hypothesis testable, and matched to the available evidence. He also indicated that there were obvious geographical barriers that were the likely cause of speciation.

[[Stephen Jay Gould]] asserted that Agassiz's observations sprang from racist bias, in particular from his revulsion on first encountering African-Americans in the United States.<ref>{{Cite book |last=Jay. |first=Gould, Stephen |url=http://worldcat.org/oclc/212909101 |title=The mismeasure of man |date=2008 |publisher=W.W. Norton |isbn=978-0-393-31425-0 |oclc=212909101}}</ref> Referencing letters written by Agassiz, Gould compares Agassiz' public display of dispassionate objectivity to his private correspondence, in which he describes "the production of half breeds" as "a sin against nature..." Describing the interbreeding of white and black people, he warns, "We have already had to struggle, in our progress, against the influence of universal equality... but how shall we eradicate the stigma of a lower race when its blood has once been allowed to flow freely into our children." In contrast, others have asserted that, despite favoring polygenism, Agassiz rejected racism and believed in a spiritualized human unity. However, in the same article, Agassiz asks the reader to consider the hierarchy of races, mentioning "The indomitable, courageous, proud Indian, – in how very different a light he stands by the side of the submissive, obsequious, imitative negro, or by the side of the tricky, cunning, and cowardly Mongolian! Are not these facts indications that the different races do not rank upon one level in nature?"

Agassiz never supported [[slavery]] and claimed his views on polygenism had nothing to do with politics.<ref name=":02" /> His views on polygenism have been claimed to have emboldened proponents of slavery.

Accusations of racism against Agassiz have prompted the renaming of landmarks, schoolhouses, and other institutions (which abound in Massachusetts) that bear his name. Opinions about those moves are often mixed, given his extensive scientific legacy in other areas, and uncertainty about his actual racial beliefs. In 2007, the [[Swiss Federal Council|Swiss government]] acknowledged his "racist thinking", but declined to rename the Agassizhorn summit. In 2017, the [[Swiss Alpine Club]] declined to revoke Agassiz's status as a member of honor, which he received in 1865 for his scientific work, because the club considered that status to have lapsed on Agassiz's death. In 2020, the [[Stanford University|Stanford]] Department of Psychology asked for a statue of Louis Agassiz to be removed from the front façade of its building. In 2021, Chicago Public Schools announced they would remove Agassiz's name from an elementary school and rename it for the [[Abolitionism in the United States|abolitionist]] and political activist, [[Harriet Tubman]]. In 2022, [[The Trustees of Reservations]] renamed Agassiz Rock as [[The Monoliths (Manchester-by-the-Sea)|The Monoliths]].<ref>{{cite news |title=North Shore park drops name of 19th-century scientist who promoted racist beliefs |url=https://www.bostonglobe.com/2022/02/28/metro/north-shore-park-drops-name-19th-century-scientist-who-promoted-racist-beliefs/|work=Boston Globe |date=28 Feb 2022}}</ref>

==Works==
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* ''[https://www.biodiversitylibrary.org/bibliography/4275 Recherches sur les poissons fossiles]'' (1833–1843)
* ''History of the Freshwater Fishes of Central Europe'' (1839–1842)
* ''[https://catalog.hathitrust.org/Record/100170940 Études sur les glaciers]'' (1840)
* ''[https://www.biodiversitylibrary.org/bibliography/1126 Études critiques sur les mollusques fossiles]'' (1840–1845)
* ''[https://www.biodiversitylibrary.org/bibliography/49761 Nomenclator Zoologicus]'' (1842–1846)
* ''[https://www.biodiversitylibrary.org/bibliography/5752 Monographie des poissons fossiles du Vieux Gres Rouge, ou Systeme Devonien (Old Red Sandstone) des Iles Britanniques et de Russie]'' (1844–1845)
* ''[https://www.biodiversitylibrary.org/bibliography/20707 Bibliographia Zoologiae et Geologiae]'' (1848)
* (with [[Augustus Addison Gould|A. A. Gould]]) [https://archive.org/details/principleszolog02goulgoog ''Principles of Zoology for the use of Schools and Colleges''] (Boston, 1848)
* ''[https://www.biodiversitylibrary.org/bibliography/1827 Lake Superior: Its Physical Character, Vegetation and Animals, compared with those of other and similar regions]'' (Boston: Gould, Kendall and Lincoln, 1850)
* ''[https://www.biodiversitylibrary.org/bibliography/12644 Contributions to the Natural History of the United States of America]'' (Boston: Little, Brown, and Co., 1857–1862)
* ''[https://archive.org/details/geologicalsketc04agasgoog Geological Sketches]'' (Boston: Ticknor & Fields, 1866)
* ''[https://archive.org/details/journeyinbrazil00agas3 A Journey in Brazil]'' (1868)
* ''[https://www.biodiversitylibrary.org/bibliography/21409 De l'espèce et de la classification en zoologie]'' [''Essay on classification''] (Trans. Felix Vogeli.  Paris: Bailière, 1869)
* ''[https://books.google.com/books?id=eczaAAAAMAAJ Geological Sketches (Second Series)]'' (Boston: J.R. Osgood, 1876)
* [https://www.questia.com/library/book/essay-on-classification-by-louis-agassiz-edward-lurie.jsp ''Essay on Classification''], by Louis Agassiz (1962, Cambridge)

==Taxa described by him==
*See [[:Category:Taxa named by Louis Agassiz]]

==See also==
* [[List of geologists]]

==References==
{{Reflist}}

==Sources==
* {{Cite news |pmid =11616944 |last=Dexter |first=R W |publication-date=1979 |year=1979 |title=The impact of evolutionary theories on the Salem group of Agassiz zoologists (Morse, Hyatt, Packard, Putnam) |volume=115 |issue=3 |periodical=Essex Institute Historical Collections
|pages=144–171 }}
* {{cite book|last=Emling|first=Shelley|author-link=Shelley Emling|title=The Fossil Hunter: Dinosaurs, Evolution, and the Woman whose Discoveries Changed the World |publisher=Palgrave Macmillan|year=2009|isbn=978-0-230-61156-6}}
* {{cite book |last=Irmscher |first=Christoph |title=Louis Agassiz: Creator of American Science |year=2013 |publisher=Houghton Mifflin Harcourt |isbn=978-0-547-57767-8 |url=https://archive.org/details/louisagassiz00chri |url-access=registration }}
* {{Cite news |pmid = 13232804|last=Lurie|first=E|publication-date=Sep 1954|year=1954|title=Louis Agassiz and the races of Man|volume=45 |issue=141|periodical=Isis; an International Review Devoted to the History of Science and Its Cultural Influences
|pages=227–42 }}
* {{cite book |last=Lurie |first=Edward |title=Louis Agassiz: A Life in Science |year=1988 |publisher=Johns Hopkins University Press |isbn=978-0-8018-3743-2 |url-access=registration |url=https://archive.org/details/louisagassizlife00luri }}
* {{cite encyclopedia |last=Lurie |first=Edward |title=Agassiz, Jean Louis Rodolphe |encyclopedia=Complete Dictionary of Scientific Biography |volume=1 |location=Detroit
|publisher=Charles Scribner's Sons |year=2008 |pages=72–74|url=http://go.galegroup.com.prox.lib.ncsu.edu/ps/i.do?id=GALE%7CCX2830900053&v=2.1&u=ncsu_main&it=r&p=GVRL&sw=w}}
* {{Cite news |pmid = 2573108 |last=Mackie |first=G O |author-link=George Owen Mackie |publication-date=1989 |year=1989 |title=Louis Agassiz and the discovery of the coelenterate nervous system |volume=11 |issue=1 |periodical=History and Philosophy of the Life Sciences |pages=71–81 }}
* {{cite book |last=Menand |first=Louis |author-link=Louis Menand |title=The Metaphysical Club: A Story of Ideas in America |year=2002 |publisher=Macmillan |isbn=978-0-374-52849-2 |pages=97–116 |url=https://books.google.com/books?id=-hpHYbwdCCk |chapter=Agassiz}}
* {{cite book |last=Numbers |first=Ronald L. |author-link=Ronald Numbers |title=The Creationists: From Scientific Creationism to Intelligent Design |edition=Expanded |year=2006 |isbn=978-0-674-02339-0 |publisher=Harvard University Press |location=Cambridge, MA}}
* {{cite book |last=Rogers |first=Molly |title=Delia's Tears: Race, Science, and Photography in Nineteenth-Century America|year=2010 |publisher=Yale University Press|isbn=978-0-300-11548-2|url=https://books.google.com/books?id=o91HLeOhZQYC}}
* Smith, Harriet Knight, ''The history of the Lowell Institute'', Boston:  Lamson, Wolffe and Co., 1898.
* {{Cite news |pmid = 11610990 |last=Winsor |first=M P |publication-date=1979 |year=1979 |title=Louis Agassiz and the species question |volume=3 |periodical=Studies in History of Biology |pages=89–138 }}
* {{cite Appletons|wstitle = Agassiz, Jean Louis Rudolphe}}

'''Attribution:'''
* {{EB1911|wstitle=Agassiz, Jean Louis Rodolphe |first=Horace Bolingbroke |last=Woodward |author-link=Horace Bolingbroke Woodward |volume=1 |pages=367–368}}
*{{BDA1906|wstitle=Agassiz, Jean Louis Rudolphe |volume=1 |pages=60–64}}

==Archive sources==
A collection of Louis Agassiz's professional and personal life is conserved in [[:fr:Archives de l'État de Neuchâtel|the State Archives of Neuchâtel]]. 
*{{cite archive |fonds = Louis Agassiz (1817–1873) |collection = Agassiz Louis  |collection-url = https://floraweb.ne.ch/flora/ark:/37964/00175 |institution = [[:fr:Archives de l'État de Neuchâtel|Archives de l'État de Neuchâtel]] }}

==External links==
{{sister project links|auto=1|author=1|species_author=1}}
* {{Helveticat}}
* {{Gutenberg author |id=1935| name=Louis Agassiz}}
* {{Internet Archive author |sname=Louis Agassiz}}
* {{Librivox author |id=362}}
* [https://www.biodiversitylibrary.org/creator/1366 Works by Louis Agassiz] online at the [[Biodiversity Heritage Library]].
* {{ScienceWorldBiography | urlname=Agassiz | title=Agassiz, Jean (1807–1873)}}
* Pictures and texts of [https://web.archive.org/web/20100811220546/http://www3.unil.ch/viatimages/index.php?module=search&projet=viaticalpes#/ouvrage-141 ''Excursions et séjours dans les glaciers et les hautes régions des Alpes''] and of [https://web.archive.org/web/20100811220546/http://www3.unil.ch/viatimages/index.php?module=search&projet=viaticalpes#/ouvrage-135 ''Nouvelles études et expériences sur les glaciers actuels''] by Louis Agassiz can be found in the database VIATIMAGES.
* [http://www.wku.edu/~smithch/biogeog/AGAS1850.htm "Geographical Distribution of Animals"] {{Webarchive|url=https://web.archive.org/web/20090622011725/http://www.wku.edu/~smithch/biogeog/AGAS1850.htm |date=June 22, 2009 }}, by Louis Agassiz (1850)
* ''[[Runner of the Mountain Tops: The Life of Louis Agassiz]]'', by [[Mabel Louise Robinson]] (1939) – [http://digital.library.upenn.edu/women/robinsonml/runner/runner.html free download] at ''A Celebration of Women Writers'' – UPenn Digital Library
* [http://research.amnh.org/ichthyology/neoich/expeditions/thayer.html Thayer Expedition to Brazil, 1865–1866] {{Webarchive|url=https://web.archive.org/web/20090925070607/http://research.amnh.org/ichthyology/neoich/expeditions/thayer.html |date=September 25, 2009 }} (Agassiz went to Brazil to find glacial boulders and to refute Darwin. [[Dom Pedro II]] gave his support for Agassiz's expedition on the Amazon River.)
* [https://web.archive.org/web/20120112155252/http://oasis.lib.harvard.edu/oasis/deliver/deepLink?_collection=oasis&uniqueId=hou00416&digital=y Louis Agassiz Correspondence], [[Houghton Library]], [[Harvard University]]
* [https://www.flickr.com/photos/bibliodyssey/sets/72157613064476121/ Illustrations from 'Monographies d'échinodermes vivans et fossiles']
* [http://www.nasonline.org/publications/biographical-memoirs/memoir-pdfs/agassiz-louis.pdf National Academy of Sciences Biographical Memoir]
* Agassiz, Louis (1842) [http://lhldigital.lindahall.org/cdm/ref/collection/ice/id/1658 "The glacial theory and its recent progress"] {{Webarchive|url=https://web.archive.org/web/20200708220551/http://lhldigital.lindahall.org/cdm/ref/collection/ice/id/1658 |date=July 8, 2020 }} ''The Edinburgh New Philosophical Journal, vol. 33''. p.&nbsp;217–283. ([[Linda Hall Library]])
* Agassiz, Louis (1863) [http://lhldigital.lindahall.org/cdm/ref/collection/nat_hist/id/8523 ''Methods of study in natural history''] – ([[Linda Hall Library]])
* [http://www.scottishgeology.com/geo/regional-geology/midland-valley/agassiz-rock-edinburgh/ Agassiz Rock, Edinburgh] {{Webarchive|url=https://web.archive.org/web/20210121151635/https://www.scottishgeology.com/geo/regional-geology/midland-valley/agassiz-rock-edinburgh/ |date=January 21, 2021 }} – during a visit to Edinburgh in 1840, Agassiz explained the striations on this rock's surface as due to glaciation

{{Natural history}}
{{Copley Medallists 1851-1900}}
{{Hall of Fame for Great Americans}}
{{Historical definitions of race}}

{{Authority control}}

{{Portal bar|Biography|Earth sciences|Geology|History of science|Switzerland|United States}}

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