Correspondence, manuscripts, documents, reports, and printed material of Hughes. The papers cover primarily the period following Hughes' defeat in the 1916 presidential election up to his appointment as Chief Justice of the Supreme Court in 1930; in most files there is a gap from March 1921 to March 1925, when Hughes was Secretary of State. Some materials relate to the law firm of Hughes, Rounds, Schurman and Dwight (later Hughes, Schurman and Dwight), but primarily concern Hughes' philanthropies and activities in professional organizations. Among these latter associations are the American Bar Association, the Association of the Bar of the City of New York, the Legal Aid Society, and the New York State Bar Association. Records for a number of Hughes' cultural, educational, and international philanthropies, such as the Armenian National Union of America and the George Washington Memorial Association, are included as are materials on his participation in the 1918-1924 aircraft investigation, the Sixth Pan American Conference (Havana, 1928), and the Permanent Court of International Justice, the Hague.

Prominent correspondents include Benjamin N. Cardozo, Calvin Coolidge, William H.P. Faunce, Felix Frankfurter, William D. Guthrie, Warren G. Harding, Herbert Hoover, J. Edgar Hoover, Jean Jules Jusserand, Frank B. Kellogg, Frances Kellor, Fiorello H. La Guardia, James Grover McDonald, John D. Rockefeller, Jr., Franklin D. Roosevelt, Theodore Roosevelt, Elihu Root, Leo S. Rowe, Alfred E. Smith, Harlan Fiske Stone, Henry W. Taft, William Howard Taft, Sumner Welles, and George W. Wickersham.