Papers of the American lawyer and politician. U.S. Senator from New York; President of the New York Central Railroad. Outgoing business and personal correspondence. The correspondence also contains items of a more personal nature, including acceptances and refusals of speaking invitations, requests for meetings, arrangements for social engagements, and personal notes. There are also a number of items associated with Depew's retirement years during which he was frequently approached for reminiscences about various individuals.

Papers of the American lawyer, legislator, politician. New York State Senator representing Onondaga County, and Lieutenant Governor, later Governor, upon the resignation of Charles Evans Hughes. Correspondence (1900-1912), includes 4400 incoming letters and 4000 outgoing carbons; personal financial records (1903-1914); speeches; and photographs. Correspondents include Nicholas Murray Butler, George Fisk Comfort, Chauncey M. Depew, Alan C. Fobes, Frank W. Higgins, Charles Evans Hughes, Seth Low, Frank A. Munsey, Benjamin B. Odell, Thomas C. Platt, Elihu Root, Jacob G. Schurman, William H. Taft, James W. Wadsworth, Andrew Dickson White, and other White family members, and Timothy L. Woodruff.

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.