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, and printed files. The papers deal mostly with Greene's academic career as a history professor at University of Illinois and at Columbia University; with his activities in various professional and social organizations; and, to a lesser extent, his travels, studies, and personal and family matters. Among the major correspondents are such public figures as Louis D. Brandeis, Felix Frankfurter, and James Jules Jusserand; and such prominent historians as James Truslow Adams, Henry Steele Commager, Samuel Eliot Morison, Richard B. Morris, and Allan Nevins.

Correspondence, manuscripts, and notes. This collection contains the manuscripts for most of his books and articles. There are also copies of his many book reviews and articles by other authors analyzing the impact of his interpretations of American history. The correspondents include: H.S. Commager, C. Vann Woodward, Stuart Bruchey, S.E. Morison, Clarence Ver Steeg, Alfred A. Knopf, Helen Frankenthaler, Arthur Schlesinger, Jr., and others. There are also 70 books from his library