Whitelaw Reid papers consist of correspondence, letterbooks, diaries, manuscripts of speeches and articles, reports, scrapbooks, printed matter, biographer's notes, photographs, and memorabilia particularly relating to Reid's ambassadorship to Great Britain and to extradition and commercial treaties with France, Spanish-American War treaty negotiations, and Newfoundland fisheries negotiations. Other topics include the Franco-Prussian War, the erection of the New York Tribune building, the "cipher dispatches" concerning the Hayes-Tilden presidential election of 1876, the beginning of the Tribune's Fresh Air Fund in 1879, opposition to Roscoe Conkling in the New York Republican Party, the Mergenthaler linotype machine, and the 1892 Homestead Strike. Also includes a file on Horace Greeley, founder of the New York Herald Tribune and Reid's mentor and partner. Correspondents include Oliver Wendell Holmes, John E. Milholland, and Elihu Root. Other correspondents of Whitelaw Reid are indexed in an appendix to the finding aid for the collection.

Elisabeth Mills Reid papers include family and personal correspondence and business and financial papers pertaining to social and political life in Washington, D.C., and New York, N.Y., diplomatic circles in London, and her philanthropic work for the American Red Cross, Bellevue Hospital Training School for Nurses, New York, N.Y., and other medical facilities. Correspondents include Franklin P. Adams, Mabel Thorp Boardman, Charles Henry Brent, Anna Roosevelt Cowles, Virginia Crocheron Gildersleeve, Frederick Huntington Gillett, Walter Lippmann, Darius O. Mills, Ogden Mills, Helen Rogers Reid, and Mark Sullivan.

Ogden Mills Reid papers consist of correspondence, trip diary, financial papers, subject file, and other papers relating to the amalgamation of the New York Tribune and New York Herald, the European edition of the New York Herald Tribune during World War II, and Reid's visit to the Far East following the war and interviews with Douglas MacArthur and Chiang Kai-shek. Correspondents include John V. Babcock, Richard Evelyn Byrd, Royal Cortissoz, Frederic R. Coudert, Laurence Hills, Harold L. Ickes, Leon L. Lewis, Edward G. Longman, George H. Moses, John J. Pershing, Fred B. Pitney, Elisabeth Mills Reid, Theodore Roosevelt, and Leonard Wood.

Helen Rogers Reid papers span the years 1903 to 1970, comprising the bulk of the collection, and consist of correspondence, speeches and writings, financial papers, subject file, and other papers chiefly relating to her career at the New York Herald Tribune as director of advertising (1918), vice president (1922), and president (1947). Includes material on the newspaper's New York Herald Tribune Forum and its stand on political issues. Other topics include her work on behalf of Barnard College, the Fresh Air Fund, New York University, women's suffrage, and the President's Commission on the Status of Women. Correspondents include Jospeh Alsop, Bert Andrews, Lois A, Barrett, André Bing, Heywood Broun, Calvin Coolidge, Royal Cortissoz, Gladys V. Draper, Dwight D. Eisenhower, Fanny Fern Fitzwater, Eric Hawkins, Elsie M. Hill, Herbert Hoover, Selwyn Lezard, Walter Lippmann, Lucie Noël, Geoffrey Parsons, Franklin D. Roosevelt, Marcel M. Tallin, Dorothy Thompson, Kay Thorpe, Francis B. Trudeau, Harry S. Truman, Purificacion C. Valera, and Irita Taylor Van Doren.

Reid Foundation records established to grant funds to journalists for work and study abroad following World War II, consist of correspondence, applications, resumes, articles, printed matter, and photographs. Grant recipients included Ben H. Bagdikian and Jules Witcover.