Correspondence, biographical sketches, genealogies, Bible records, public documents, notes, photos, and other papers, reflecting Hoyt's genealogical and historical interests and his activities with Office of the Paymaster General and Massachusetts Treasury Office. Includes materials relating to the Freeman, Hoyt, Marshall, McClenachan, Randolph, and Stuart families.

Among the documents collected by Col. Hoyt is the journal (1751-1753) of William Smith (b. 1702), describing his duty on Sable Island, N.S.; information pertaining to the safety measures taken by the British merchant marine, the Massachusetts and Connecticut boundary, financial affairs during the American Revolution, and Portsmouth, N.H., branch of Bank of the United States; and letters from Admiral Asa Walker discussing the outbreak of the Philippine Insurrection in 1899, Alexander Hamilton concerning U.S. Dept. of the Treasury matters, and John C. Calhoun pertaining to military pensions. Other persons represented include Timothy Bigelow, Mary Billingham, Greenfill Blake, Joshua Brackett, George G. Byron, Henry Clay, Garrett Cottringer, Mary A.R. Lee, Benson J. Lossing, Dolly Madison, Robert Morris, Joseph Nye, Zerviah Parker, Martin Van Buren, George Washington, and William Whipple.