Simon Flexner, born in 1863, one of the nation's leading experts in pathology and bacteriology, was most renowned for his research on cerebrospinal meningitis, polio and infantile paralysis. Arguably though, Flexner's stewardship of the Rockefeller Institute was his greatest contribution to medical and scientific research. His rise in the medical community began in the late nineteenth century in Louisville, Kentucky, where despite not having completed even the seventh grade, Flexner taught himself basic bacteriology by conducting experiments at home using a microscope borrowed from the pharmacy where he served as an apprentice. Granted a medical degree from the University of Louisville School of Medicine in 1889, he went on to a pathology fellowship at the newly opened John Hopkins School of Medicine. Within two short years of leaving Louisville, Flexner received an assistant of pathology appointment at Johns Hopkins. It was a quick ascent and the beginning of a long and brilliant career that included a prestigious appointment at the University of Pennsylvania and then a directorship at the new Rockefeller Institute where he realized his lifelong dream of creating a dynamic and productive research laboratory. The Rockefeller Institute became instantly famous worldwide as the preeminent research facility for virology and under Flexner's direction produced invaluable contributions in pathology, bacteriology, and immunology. This collection does not reflect the early phases of Flexner's career at Johns Hopkins but does document an early interest in meningitis and other infectious diseases with science-related correspondence, laboratory notebooks, and administrative correspondence with the New York City and State Departments of Health. There is abundant material on Flexner's directorship of the Rockefeller Institute for Medical Research, including Flexner's search for staff, an involved process which is detailed in correspondence with the scientists, many of whom became quite famous. Also included is material relating to the other institutions and Rockefeller philanthropies with which Flexner was involved. (Among the most significant correspondence, however, may be that which documents the support of the General Education Board and the Rockefeller Foundation in the development and subsequent reorganization of medical schools following brother Abraham Flexner's scathing report on medical education in the United States and Canada). This collection would be of great interest to anyone interested in the history of bacteriology, histology, and immunology or the general history of modern medicine and philanthropy.

The bacteriologist and virologist Thomas Milton Rivers spent over thirty years at the Rockefeller Institute as a researcher in the Department of Bacteriology and from 1937-1955, as Director. Working on measles and pneumonia, Rivers discovered the parainfluenzae bacillus and cultivated vaccine virus for human use, and during the 1950s, he played an important role in coordinating research on poliomyelitis as head of the National Institute for Infantile Paralysis. During the Second World War, Rivers led the Naval Medical Research Unit in the South Pacific, rising to the rank of Rear Admiral. The Rivers Papers contains correspondence, laboratory notes, speeches, and photographs documenting Rivers' activities at the Rockefeller Institute, the development of polio vaccine, and Rivers' Navy experience in the Pacific during World War II.

Correspondence, notebooks, research data related to Cole's career as the first director at the Hospital of the Rockefeller Institute of Medical Research, 1908-1937. His research of pneumonia was conducted when the disease was epidemic. Personal correspondence reflect Cole's life as a medical resident at Johns Hopkins, 1899-1908. Documented are his memberships in leading medical organizations throughout his career, including the Association of American Physicians and the New York Academy of Medicine. This collection showcases the evolving changes in the medical profession from practicing physician to clinician.

Eugene Opie spent most of his career as a pathologist at the Rockefeller Institute engaged in research on the influenza, tuberculosis, blood diseases, poliomyelitis, and viruses. His work at Washington University, St. Louis, is documented, as are his efforts to alleviate tuberculosis in Jamaica, among Philadelphia schoolchildren, and in New York City. The Opie collection contains correspondence, notebooks, lab notes from his days at Rockefeller, articles, reprints, and photographs. Opie's long interest in China is reflected in material on the American Bureau for Medical Aid to China, the United China Relief, and Chinese medicine in general. There is also significant documentation on the International Health Division of the Rockefeller Foundation, the Henry Phipps Institute of the University of Pennsylvania, the Milbank Memorial Fund, and other institutions. There are also reports of approximately 300 clinical autopsies performed at the Base Hospital, Camp Pike, Ark., of soldiers who died in the flu epidemic of 1918. Also there are notes of Opie's course in pathology at the University of Pennsylvania.

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.