Louis Jean Rodolph Agassiz papers, 1833-1873


Date: 1833-1873 | Size: 50 items


A miscellaneous collection of letters written by naturalist Louis Jean Rodolph Agassiz concerning a wide range of topics: natural history and naturalists, geology, mineralogy, fossils, publications, expeditions, and the Museum of Comparative Zoology at Harvard, which he founded.

Background note

Louis Agassiz (1807-1873, APS 1843) was a zoologist and geologist. A student of Georges Cuvier, Agassiz was renown for his six-volume work Poissons fossils, a study of more than 1,700 ancient fish. Equally important was his Ètudes sur les glaciers (1840). In 1845 Agassiz moved to the United States on a two-year study grant from King Friedrich Wilhelm IV of Prussia to compare the flora and fauna of the United States and Europe. While in the United States he was invited to deliver a course of lectures at the Lowell Institute in Boston. He took America and New England by storm and as a result in 1847 was appointed professor of zoology and geology at Harvard's new Lawrence Scientific School.

Jean Louis Rodolphe Agassiz was born in Motier, Switzerland on May 26, 1807, the son of a Protestant minister Rodolphe Agassiz and his wife Rose Mayor. Despite family pressure to enter business, Agassiz early decided to devote himself to the study of nature. At the age of twenty-one he predicted that he would become "the first naturalist of his time, a good citizen and a good son." His determination gained Agassiz an excellent education in the natural sciences at the Universities of Heidelberg and Munich. He also made important contacts in early life that formed his outlook and provided the basis for his early career. The naturalist Johann B. Spix allowed him to publish on a collection of fish from Brazil that Spix had gathered, while the anatomist Ignaz Döllinger trained him to use the microscope and introduced him to the field of embryology. Philosophically, Agassiz was influenced by the German idealism of Lorenz Okenfuss, who built a system of biological classification based upon increasing complexity of sense organs. Agassiz's scientific thought and practice was characterized by two separate and often contradictory outlooks. One was exact and pragmatic; the other was transcendental. His approach was clearly influenced by French zoologist and paleontologist Georges Cuvier, who passed on to Agassiz his remarkable collection of fossil fish illustrations. He also impressed the geographer Alexander Humboldt, an adviser to the king of Prussia who arranged an appointment for him at the Collège de Neuchâtel in 1832, where he taught natural history for more than ten years. During these years (1832-42) he studied fossil fish in museums and private collections throughout Europe, resulting in his six-volume Poissons fossils that described more than 1,700 primeval fish, that he analyzed according to Cuvier's comparative method. The work, which won high praise from major Bristish naturalists Sir Charles Lyell and Richard Owen, provided the basis for Agassiz's scientific fame and fortune. His natural philosophy was infused with the belief in an all-powerful diety, who planned and created every single living being, plant and animal, undercutting any genetic connection between ancient and modern creatures.

In addition to his work on fish, between 1837 and 1843 Agassiz did ground breaking work on glacial geology, presented in a paper presented to the Sociètè Helvétique des Sciences naturelles (July 1837) and in his book Etudes sur les glaciers in which he theorized that a massive glacier had once covered all of Europe. Although the idea had first been suggested by Swiss naturalist Jean de Charpentier, Agassiz was the first to publicize the idea and to apply it to all of Europe. A prolific writer, who wished to be personally involved with the production of his works, Agassiz developed a publishing house in Neuchâtel, that employed the latest technology in photo duplication and produced bibliographies, dictionaries and monographs by Agassiz and his assistants. In the spring of 1845 Agassiz's fortunes abruptly shifted. His wife Cécile Braun Agassiz left her husband and Neuchâtel, his printing business closed due to accumulated debts, and he was forced to leave the Collège de Neuchâtel. Just as his luck seemed to run out, he received word of a 2-year grant secured for him by Humboldt from King Friedrich Wilhelm IV of Prussia for $3,000 to do a comparative study of the flora and fauna of the United States and Europe.

Shortly after the arrival of Agassiz in the United States, John Amory Lowell, manufacturer and head of the Lowell Institute in Boston, invited him to deliver a course of public lectures. New Englanders found the Swiss naturalist, who spoke enthusiastically about primitive fish and prehistoric glaciers, intriguing. New England scientific luminaries such as Harvard botanist Asa Gray and Yale chemist Benjamin Silliman lauded Agassiz as "full of knowledge on all subjects of science." His lectures created such a demand for speaking engagements, that within less than two years Agassiz was able to repay $20,000 in European debt. In the fall of 1847 Harvard University offered him a chair of zoology and geology at its newly established Lawrence Scientic School. In July 1848, after his wife's death, he arranged for his children to join him in the United States. These events, together with his 1850 marriage to a bright well-connected Bostonian Elizabeth Cabot Carey, sixteen years Agassiz's junior, permanently anchored the Swiss scientist in America. Soon afterward Agassiz's home in Cambridge became a center of intellectual life. As a Harvard professor he badgered the University continually for funds to build a major natural history museum to instruct the public and help to train advanced students. His efforts paid off in November 1859, when the Museum of Comparative Zoology opened its doors. The Museum provided a unique resource for American students to gain unrestricted, first hand access to natural specimens. Many practicing American naturalists of the late nineteenth and early twentieth centuries were trained by Agassiz and worked in his museum. The Museum testified to Agassiz's passion for collecting and identifying the "entire natural kingdom all at once," a desire that quickly filled the repository to overflowing with specimens. From a philosophical perspective Agassiz planned the Museum as a demonstration of the "master plan" that the diety had executed in the creation of the natural world, displaying the "type plan" of different classes and stressing the separate creation of each species. Agassiz's core belief in the special creation of species by God undergirded his quest to locate new species. However, some colleagues criticized him as "species mad," arguing that his museum and his methods added little to the conceptual understanding of natural history.

Agassiz's reputation took a major hit in a series of Boston debates on evolution, after the publication of Charles Darwin's Origin of Species in 1859. Agassiz made a poor defense of special creation against Darwin's defenders Asa Gray and William Barton Rogers. Furthermore, Agassiz's understanding of special creationism as applied to human beings led him to view various races as distinct species, a rationale quickly adopted by the proponents slavery, who asserted a scientific basis to white supremecy.

Concerned about the decline of his professional reputation in the 1850s, in 1855 Agassiz announced the forthcoming publication of a projected ten-volume entitled Contributions to the Natural History of the United States of America. A total of 2,500 subscribers made advanced purchases at $12.00 each. The initial volume entitled Essay on Classification elaborated Agassiz's views on classification, the philosophy of nature and the species concept. Appearing two years after Darwin's Origin of Species, the work drew mixed reviews. Many were put off by the author's dogmatism, others thought his views dated and moribund. Three more volumes appeared, but the publication of the projected set was never completed.

Many years later in 1872 Agassiz did reconsider evolution, trying to understand Darwin's views by making a trip around South America, retracing Darwin's voyage. However, he only became more convinced that the concept of evolution was "a scientific mistake, untrue to the facts, unscientific in its method, and mischievous in its tendency." To the dismay of the scientific community Agassiz authored strident attacks on Darwinism in the popular press, infuriating Asa Gray and James Dana. Consequently, Agassiz was increasingly excluded from the politics of American science.

Agassiz remained at Harvard University until the end of his life. When he died at Cambridge, Massachusetts, he was deeply mourned by his adopted country.

Collection Information

Physical description

16 items, .25 linear feet.

16 items, .25 linear feet.


Variously acquired, including purchases from Paul Richards, Joseph Rubinfine, Charles Hamilton, Winifred Myers, Julia Sweet Ne. See in-house shelf list for additional accession dates and numbers.

Related material

There are additional Agassiz letters indexed in other collections at the American Philosophical Society.

Early American History Note

The collection of Louis Agassiz correspondence consists of approximately fifty letters that discuss a wide range of topics at the fore of scientific thought in the mid to late nineteenth century. Many letters are short acknowledgements sent to various friends and acquaintances. Some letters are in French, although most are in English and are addressed to American correspondents. Topics of longer letters include his views on the origins of mankind and races, plant life in the Caribbean, and the possible scientific causes for "spiritual manifestations." Most letters date from 1850 onward and are thus outside the scope of this guide.

Indexing Terms

Corporate Name(s)

  • Harvard University. Museum of Comparative Zoology.

Personal Name(s)

  • Agassiz, Louis, 1807-1873
  • Buckland, William, 1784-1856
  • Davis, Charles Henry, 1807-1877
  • Eliot, Charles William, 1834-1926
  • Emery, Charles Edward, 1838-1898
  • Gray, Asa, 1810-1888
  • Gray, John Edward, 1800-1875
  • Hartt, Charles Frederick, 1840-1878
  • Haven, Franklin, 1857-1908
  • Hyatt, Alpheus, 1838-1902
  • Kidder, Frederic, 1804-1885
  • Layard, Austen Henry, Sir, 1817-1894
  • LeConte, John L. (John Lawrence), 1825-1883
  • LeConte, Joseph, 1823-1901
  • Lesquereux, Leo, 1806-1889
  • McLane, Allen, 1746-1829
  • Milne-Edwards, H. (Henri), 1800-1885
  • Parsons, Thomas William, 1819-1892
  • Wilson, Henry, 1812-1875
  • Winsor, Justin, 1831-1897


  • Fossils -- Collection and preservation.
  • Geology -- Research -- United States.
  • Mineralogy - Research - United States
  • Natural history museums -- Massachusetts.
  • Natural history.
  • Naturalists.
  • Religion
  • Science and technology
  • Scientific expeditions.
  • Zoological museums -- Massachusetts.
  • Zoology.

Detailed Inventory

Agassiz, Louis, 1807-1873.
Feb. 26, 18407x4-1/2

Inverary Castle, A.N.S. 1p.In French. Explanatory note relative to the Duke of Argyll's interest in natural history.

General physical description: 7x4-1/2

Other Descriptive Information: See: See also:

Agassiz, Louis, 1807-1873.
Letter to Henry Randall, Courtland City, N.Y.;
June 18, 184810-1/2x8-1/2

Cambridge, Mass., A.L.S. 1p.add. Friendly letter. Packages being sent to Verneuil and Europe. Would like to exchange fossils.

General physical description: 10-1/2x8-1/2

Agassiz, Louis, 1807-1873.
Letter to A[sa] Gray;
Aug. 5, 18496-1/4x4

Cambridge, A.L.S. 1p.

General physical description: 6-1/4x4

Agassiz, Louis, 1807-1873.
Letter to Mrs. Bowen;
June 5, 18557x4-3/4

Cambridge, Mass., A.L.S. 1p. Unable to attend a wedding?

General physical description: 7x4-3/4

Other Descriptive Information: See: See also:

Agassiz, Louis, 1807-1873.
Letter to Edward Habick
May 6, 1859 

A.L.S. 2p.

Agassiz, Louis, 1807-1873.
Letter to Geo[rge] B[ruce] Upton;
July 16, 18608x5

Nahant, A.L.S. 1p.and end. Will accept his daughter as a pupil.

General physical description: 8x5

Other Descriptive Information: See: See also:

Agassiz, Louis, 1807-1873.
Letter to Ch[arles] E[dward] Emery;
July 26, 18608x5

Cambridge, Mass., A.L.S. 1p. Received shells from Emery. Wishes to correspond and exchange discoveries.

General physical description: 8x5

Agassiz, Louis, 1807-1873.
Letter to Geo[rge] Ticknor, Esq.;
December 4, 18614-1/2x7

Cambridge, A.L.S. 1p. Declines invitation for Thursday; has wanted to see Ticknor "for some weeks."

General physical description: 4-1/2x7

Other Descriptive Information: See: (Agassiz Papers).See also:

Agassiz, Louis, 1807-1873.
Letter to Nathanael E. Atwood;
Feb. 25, 18638x5

Cambridge, Mass., A.L.S. 1p. Thanks for the fishes.

General physical description: 8x5

Other Descriptive Information: See: See also:

Agassiz, Louis, 1807-1873.
Letter to Admiral Davis;
Aug. 10, 18648-1/4x5-1/4

A.L.S. 1p. Major Higginson gives resignation to Gen. Townsend because of poor health.

General physical description: 8-1/4x5-1/4

Agassiz, Louis, 1807-1873.
Letter to Senator H[enry] Wilson;
July 8, 186710 5/8 x 8 1/4

Nahant, ALs 2p. Responds to newspaper article; asks how "public teacher can protect himself such vilanous calumnies." Views on evolution. "Different types of the human family have an independent origin,...are not descended from common ancestors." Wilson may use letter as he pleases.

General physical description: 10 5/8 x 8 1/4

Agassiz, Louis, 1807-1873.
Letter to R[obert] C[assie] Waterston
July 10, 18692 p.

Has completed his address. Goes tomorrow to Cambridge where he will try to have his illegible work in type so that he may be able to read it himself. He shall also see how his diagrams are progressing.

Provenance: M2004-43. Purchased from Steve Resnick, October 2004

Agassiz, Louis, 1807-1873.
Letter to [Justin] Winsor;
Oct. 10, 18707-3/8x4-3/4

Bethlehem, N.H., A.L.S. 2p. Intro. to Dr. Steindachner, ichthyologist of Imperial Museum Vienna. To arrange Fish collection at Havard, and he has brought large library. Library cooperation. Mentions Stahli.

General physical description: 7-3/8x4-3/4

Agassiz, Louis, 1807-1873.
Letter to Messrs. Yellerson & Ricker, Boston;
Jan. 30, 18715 1/2 x 4 1/2

Cambridge, MA, ALS 1p. Introduces friend and "Distinguished botanist" [Leo] Lesquereux, who will take measurements of Yellerson & Ricker's tree, for exhibition purposes. Mentions Lesquereux's deafness.

General physical description: 5 1/2 x 4 1/2

Other Descriptive Information: See: See also:

Agassiz, Louis, 1807-1873.
Letter to Ch[arles] W[illiam] Eliot, Harvard Univ.;
Dec. 17, 18728x5

Cambridge, Mass., A.L.S. 3p.add. Concerns a conflict with Prof. Shaler & comments on his character. Agassiz states conditions for the State grant to the Museum, requiring free services to public schools and teachers.

General physical description: 8x5

Agassiz, Louis, 1807-1873.
Letter to Joh[annes] A[dam Simon] Oertel
May 2, 18732 p.

Cambridge, Massachusetts. Hopes Oertel will carry out his plans and visit the Amazons. Provides advice on such a visit. Folder includes typed transcript of letter.

Provenance: M2004-43. Purchased from Steve Resnick, October 2004

Agassiz, Louis, 1807-1873.
Letter to "Dear Sir;"
Aug. 18, 18738-1/4x5-1/4

Penikese Island, Mass., A.L.S. 1p. Praises A.H. Guyot's book Physical Geography. For students as well as "every investigator of kindred kindred topics."

General physical description: 8-1/4x5-1/4

Other Descriptive Information: See: See also:

Agassiz, Louis, 1807-1873.
Letter to George Trent;
Undated7 x 4 1/2

Cambridge, n.y. L.S. 2 p. Trent's argument about "invisible imponderables" has no force. Gives Spiritualists' views on essential agent in spiritual manifestations. Apologizes for dictating letter; eyes bad. 4 Jan.

General physical description: 7 x 4 1/2