The I. Ridgeway Trimble Collection spans most of his career, with the bulk of the material coming from his experiences as a lieutenant colonel in the U.S. Army Medical Corps in the South Pacific during World War II. Materials include photographs from the 118th Medical Unit, personal correspondence, U.S. Army Medical correspondence, files on body armor, hospital plans, notes for A Surgical Consultant's History of World War II, a diary kept by Trimble from 3 January 1944 to 16 January 1945, and a typescript of Trimble's diaries from 1942 to 1946. Later papers relate to Trimble's interest in the history of World War II medicine. There is material relating to Civil Defense (1959-1964) and one folder of material relating to Trimble delivering the Deaver Lecture in Philadelphia in 1972. The diaries are a rich source of information on day-to-day life in the Medical Corps. Extended entries issue from Trimble's assigned duty as Surgical Consultant "to visit the various medical installations in this area [Australia, New Guinea, Philippines], estimate the ability of the personnel, inspect the operating facilities, the sanitary arrangements, the care of the patients..." Accordingly, he describes many of the hospitals, comments on the skills of various doctors, relays facts about certain medical cases of interest, contrasts American and Australian facilities, comments on relations between the two medical corps, and describes the Australian countryside and his experiences traveling from site to site.