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.

James Lawrence Fly papers consist of correspondence, manuscripts, drafts, notes, reports, legal briefs and other documents, books, clippings, and other printed materials dealing with Fly's professional activities and relationships in all three phases of his career. Correspondents include Roger N. Baldwin, Felix Frankfurter, Cordell Hull, Elmer Rice, Franklin D. Roosevelt, and Harry Truman.

Correspondence; manuscripts of books, chapters, addresses, lectures, articles, and other writings; clippings and other printed materials relating to Butler's life and career, and memorabilia, ca. 1900-1947. Also, correspondence, 1891-1946, between Butler and presidents of the United States including William McKinley, Theodore Roosevelt, William Howard Taft, Woodrow Wilson, Warren G. Harding, Calvin Coolidge, Herbert Hoover, Franklin D. Roosevelt, and Harry S. Truman.