For his pioneering research on the link between viruses and cancer, the pathologist Francis Peyton Rous was awarded the Nobel Prize in Medicine in 1966. Working primarily at the Rockefeller Institute after 1909, Rous first came to notice for his theoretical construction of the first blood bank for use in France during World War I, a plan ultimately implemented by his assistant, Oswald H. Robertson. Subsequently, he left an important imprint on the development of experimental medicine, partly through his own research on the origins of cancer and his administrative activities at the Rockefeller, but also as editor of the Journal of Experimental Medicine from 1921-1970. The Rous Papers include correspondence, lectures, articles, reports, laboratory records, reprints, and photographs that document all aspects of the life and work of Peyton Rous. Reflecting his work at the Institute are letters of colleagues, information on assistants, and reports to the directors (1909-1959). Additional material relates to Rous' diverse organizational interests, including the American Cancer Society, Century Association, Jane Coffin Childs Memorial Fund for Medical Research (at Yale University), Federation of American Societies for Experimental Biology, Johns Hopkins University, National Academy of Sciences, National Research Council, New York Academy of Medicine, Royal Society of Medicine Foundation, and Sloan-Kettering Institute for Cancer Research.