Alfred Irving ("Pete") Hallowell was an anthropologist best known for his studies of Ojibwa culture and world-view, and the innovative use of the Rorschach Test in his studies of the psychological interrelations of individuals and their culture. Early in his career, Hallowell worked as a social case worker for Family Service, and even after moving on to study anthropology in 1920 (M.A.), he carried with him an interest in ethnic and racial culture, developing additional interests in psychological testing. Except for the years 1944-1947, when he taught at Northwestern University, Hallowell spent his entire career at the University of Pennsylvania where he was professor of anthropology, professor of anthropological psychiatry in the Medical School, and curator of social anthropology at the University Museum. A cultural anthropologist, Hallowell's use of clinical psychological methods, especially Rorschach tests, was both innovative and controversial in his discipline. In his research, he concentrated on the Algonkian Indians, especially the Abenaki and Ojibwa Indians of Canada and Wisconsin (Berens River, Lake Winnipeg, Manitoba, and Lac du Flambeau, Wisconsin areas), and the Saulteaux of Berens River. The Alfred Irving Hallowell Papers (1892-1981) contain correspondence, subject files, manuscripts of published and unpublished works by Hallowell, papers by colleagues and students, research notes kept by Hallowell, with a special emphasis on social organization, personality, behavior, psychology, religion, and folklore. The collection of several hundred photographs provides rich graphic documentation of Hallowell's work among the Ojibwa and Abnaki Indians during the 1930s.

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.