New York State Governor, 1885-1891; U.S. Senator, 1891-1897. Collection contains incoming and outgoing correspondence (chiefly political), legal papers and memorabilia.

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.