Approximately 12,000 letters to Allan Nevins from various correspondents including James Truslow Adams, Franklin Delano Roosevelt, Harry S. Truman, Willa Cather, Frances Folsom Cleveland, Van Wyck Brooks, Robert Frost, Newton D. Baker, Archibald MacLeish, John D. Rockefeller, Jr., Carl Sandburg, and Henry Wallace; notes and typescripts for Nevins' books including Emergence of Lincoln, The Ordeal of Democracy, Rockefeller, and History and Historians, with notes by editor Ray A. Billington; miscellaneous transcripts, clippings, newspapers, and photographs. Also, autograph letters and manuscripts by presidents, Civil War figures, financiers, politicians, and authors. There are also the Brand Whitlock World War I Diaries and letters to him by such people as Herbert Hoover, Gen. John J. Pershing, and others.

Correspondence, manuscripts, contracts, memos., and photographs. The correspondence pertains to the publications of numerous important fiction and non-fiction authors. The files are particularly strong for authors included in two important historical series"The New American Nation" Richard B. Morris and Henry S. Commager, editors; and "The Rise of Modern Europe" William L. Langer, editor. The files of Cass Canfield Sr. contain substantial material on Planned Parenthood and International Planned Parenthood.