The papers include correspondence, copies of his published writings, unpublished manuscripts, a large collection of handwritten sermon notes, and drafts of both his history of Quakerism and his autobiography.

The Thomas Papers include diaries, correspondence, essays, and sermon drafts illustrating the concerns and tendencies of Indiana Friends in this period. The diaries span the years of the Civil War.

The Hartley Papers consist of a diary for 1869-1870, a sermon notebook, and miscellaneous papers reflecting Hartley's career. The largest single item is an account book spanning 1876-1930.

The Merle L. Davis Papers consist of correspondence, notebooks, photographs, reports, and other materials documenting the career of Merle Leonard Davis as a Quaker minister, missionary, and administrator. The collection contains significant material for the history of the Five Years Meeting of Friends (now Friends United Meeting), Quaker missions, and Friends in Kenya and Cuba.

The Thomas E. and Esther B. Jones Collection consists of personal papers of Thomas E. Jones, the president of Fisk University from 1926 to 1946 and Earlham College from 1946 to 1958, and his wife Esther (Balderston) Jones, a missionary teacher in Japan.  It contains significant material on Quaker work in Japan, race relations, Earlham College, and Quaker affairs in the twentieth century.

The Wilson Papers consist of sermon outlines and notes primarily from the 1920s-1940s.