Papers of the American editor, railroad commissioner, executive secretary to New York State Governor Levi P. Morton. Incoming correspondence concerning railroads (Avery Andrews, Paul D. Cravath, Chauncey M. Depew, James Jerome Hill, Jeremiah Jenks, Theodore Roosevelt); politics (Thomas Collier Platt, L. Bradford Prince); the John Ericsson monument in New York City (Jonathan Scott Hartley); and the personal life of actress Louise D. (Mrs. Leslie) Carter.

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.