The papers of Ora Delmer Foster date from 1895 to 1965 and document his life and career. Autobiographical materials, memoirs, and diaries give insights into Foster's private life. His correspondence (both personal and professional) which spans seventy years is contained in five boxes. Many of his writings, especially those on Mexico and South America as well as those concerning religious issues, are included in manuscript form, with typescript drafts and notes.

Religion courses that he taught at the University of Iowa are documented in the papers with lectures, notes, research, and memoirs. Iowa's School of Religion is the subject of one entire box. Information regarding Dr. Foster's work with Comrades in Service, the American Association on Religion, and the North American Board for the Study of Religion in Higher Education is included as well. There are also boxes of photographs, books and pamphlets relating to Latin America, and slides.