Papers of the American lawyer, politician, U.S. Secretary of War under President McKinley, U.S. Secretary of State under Theodore Roosevelt, following the death of John Hay, and United States Senator from New York. Letters, 125 of which are outgoing, which include discussions concerning national and state Republican Party politics. Several letters are responses to speaking and/or dinner invitations as well as recommendations for various appointments. Correspondents include Cephas Brainerd, Henry Billings Brown, Charles Butler, Julius Chambers, Henry J. Cookinham, William E. Curtis, Charles B. Elliott, Robert Ely, John H. Finley, Henry W. Fishel, Jacob Gallinger, Paul Hickok, Frank Wayland Higgins, Willis Johnson, Adrian Joline, John Knox, Samuel Koenig, Chester Lord, Isabel Lord, William McAdoo, Richard McCurdy, Martin McMahon, Charles Miller, Benjamin B. Odell, William C. Osborn, Ellis Robb, Arthur Saunders, and others.

Papers of the Army officer; U.S. Senator (1845-1849); U.S. Secretary of the Treasury. During the Civil War, President Lincoln commissioned Dix a major-general, and ordered him to take charge of the Alexandria and Arlington Department, then reassigned him to the Department of Maryland. Dix later served as commander of the Department of the East. After the Civil War, Dix was named Minister to France (1866-1869), and following his return to the U.S., the life-long Democrat became the Republican Party nominee and the successful candidate for the Governorship of New York State (1873-1875). Includes more than 130 items of outgoing correspondence, more than half of which were written to Edwards Pierrepont between 1861 and 1877. Subjects include the Civil War, Reconstruction, New York State and national politics, and French politics and foreign relations preceding the outbreak of the Franco-Prussian War.

Papers of the Congressman from New York, United States minister to France, Vice-President of the United States, and Republican governor of New York State. Collection contains mostly incoming correspondence from clergymen, educators, financiers, journalists, and politicians. Some letters are addressed to Morton's executive secretary, Ashley W. Cole.

Papers of the New York Governor (1921 to 1922), attorney, General Counsel of U.S. Steel Corporation. Collection contains correspondence, both incoming and outgoing (1902-1958); legal briefs; writings (1922-1953); and memorabilia including family photographs and scrapbooks of political cartoons and clippings (1921-1922). Correspondents include Roger Blough, Calvin Coolidge, Richard Coughlin, Charles Crandall, Frederick Crane, Thomas E. Dewey, John Foster Dulles, Dwight D. Eisenhower, Benjamin Fairless, James A. Farley, Livingstone Farrand, James W. Fawcett, Haley Fiske, Edgar Allen Forbes, George A. Glynn, Will H. Hays, Christian Herter, Richmond Hobson, Herbert Hoover, Charles Evans Hughes, Cordell Hull, Alfred Landon, Herbert Lehman, Irving Lehman, Clayton Lusk, Albert Mann, J.P. Morgan, Irving Olds, Joseph Proskauer, Franklin D. Roosevelt, Theodore Roosevelt, Flem Sampson, Alfred E. Smith, Edward R. Stettinius, Henry Stoddard, William H. Taft, Myron Taylor, Arthur Vandenberg, Paul Vernon, Enders Voorhees, Carl Vrooman, William Wadhams, Wilbur Wakeman, John Weeks, Everett Wheeler, Horace White, and Wendell Willkie.

Papers of the Utica attorney, U.S. Senator. Outgoing correspondence primarily of a political nature, which reflects Conkling's interest in Republican Party politics at the State and national levels. Includes letters to Thomas Alvord, Henry J. Cookinham, James M. Dalzell, and Edward Ingersoll.