Frederick Henry Osborn was an administrator, humanist, and scientist. This collection includes letters, diaries, reports, speeches, drafts of articles and books, oral history interviews, and photographs. There are diaries and letters for his service in Europe with the American Red Cross during World War I. There are some letters and documents, such as patent applications and plans for inventions, from his "business career" period prior to 1928, after which he became a research associate at the American Museum of Natural History studying anthropology and population. This study led to his later important contributions to the redirection of eugenics study in the U.S. and the reorganization of the American Eugenics Society. His other related organizational work and publications relating to human and population genetics are also documented in this collection. There is significant material (letters, diaries, reports) related to Osborn's World War II contributions as the chairman of the Civilian Committee on Selective Service in 1940, and as head of the Morale Branch of the U.S. Army (later, the Information and Education Division of Special Services) in 1941. Also included are important documents, especially his diary, from his work as deputy representative on the U.S. Atomic Energy Commission and the U.N. Commission for Conventional Armaments. His letters, writings, and speeches relating to foreign policy are extensive, spanning the period from the 1940s until his death, much of it from the Vietnam War years. The correspondence with Kathleen Harris is particularly rich in this respect. There is family correspondence reflecting his dynamic philosophy of life, with long series of letters to his parents (1917-1945) and to his children and grandchildren. His later civic and regional interests, as a long-time resident of Garrison, N.Y., are evidenced in the work he did on the Palisades Interstate Park Commission.

One of the seminal figures in the emergence of the Modern or Neo-Darwinian Synthesis during the mid-twentieth century, George Gaylord Simpson (1902-1984) helped define the unique contribution made by vertebrate paleontology to the life sciences. A specialist in Mesozoic and early Cenozoic mammals, Simpson's contributions to the fusion of Darwinian natural selection and Mendelian genetics were both empirical and theoretical, culminating in his major works Tempo and Mode in Evolution and The Meaning of Evolution. From his posts at the American Museum of Natural History (1927-1959), Columbia University (1945-1959), Harvard (1959-1967), and the University of Arizona (1967-1984), Simpson became one of the most influential paleontologists of the century, helped in part by his ability to write successfully for both a technical, professional audience and a popular audience. The Simpson Papers include a comprehensive assemblage of professional and personal correspondence, reflecting nealy all phases of Simpson's career. Written with charm, wit, and a sense of literary style, the correspondence touches on all aspects of modern paleontology, providing an important perspective on the emergence of contemporary evolutionary theory, biogeography, systematic theory and methodology, the relationship of science and religion, and creationism, as well as more general issues in scientific epistemology and social and political issues. The collection also includes autobiographical data and writings, lectures, class notes and papers, research data, material on his scientific expeditions (diaries in carbon form, photos, notes, etc.), publication material (he was author of some 800 publications), extensive photographic material, diplomas, and medals.