Mainly papers of Arlington Mapes concerning his school days in Rushville (1870-78) and at Cornell University, the latter including notes taken at Professor William Dexter Wilson's lectures in the philosophy of history, his undergraduate scrapbook, correspondence (including one letter from Moses Coit Tyler), and his senior essay on American history, 1883; and records concerning his activities in later life, including two Republican Party canvass books (1890s), accounts (5 v., 1890-1925), a diary-account book (1907-12), and the articles of incorporation, bylaws, stock certificates, correspondence, and printed matter (1894-95) of the Rushville Creamery Company, of which he was secretary.

Papers of relatives include a register of electors, first election district, Gorham (1865), in the possession of Arlington's father, John W. Mapes, and a daybook and other business accounts (3 v., 1876-85) of Mapes, Sr.; a petition from residents of Ontario and Steuben Counties (ca. 1872) to President Grant asking that Richard M. Ringer, husband of Arlington's sister, Ella, be appointed mail agent on the Geneva & Hornellsville Railroad and his diaries (2 v., 1883-93); William Mapes's accounts (1 v., 1850-62); and a copybook, school merit certificates, autographs, temperance songsheet, and a scrapbook (chiefly 1840s) of Arlington's mother, Minerva Barden Mapes. [Two of the manuscript volumes noted above also contain diary entries, accounts, or penmanship exercises (1820+), presumably kept by an earlier generation.] Also, daybooks of Philip Walther (2 v., 1867-82), the first recording cash received for the sale of furniture and coffins and the second sums charged for furniture repair; manuscript and printed matter petaining to the social and civic life of Rushville, including programs and lecture ticket sale records (1889-90) of the local Amphyctyon Society; the constitution and bylaws of the Ontario County Fruit Growers' Association, organized in 1906, and programs for its 1910 and 1913 meetings; a floor plan and specifications for the Ontario County Home (1927); a pamphlet, "Guide-book to the falls and glens in and near Ithaca, N.Y."; and photographs.