Correspondence, diary, expedition journal, financial material, scientific notebook and sketches, photographs, published material, including articles and newspaper clippings, and scrapbooks. Correspondence (1854-1902) includes that of Alexander Agassiz, Charles E. Beecher, E.D. Cope, James D. Dana, J.S. Diller, G.K. Gilbert, G. Brown Goode, Asa Gray, Robert T. Hill, Anna Hyatt Huntington, Hyatt’s father, Alpheus Hyatt, Audella Beebe Hyatt, Jules Marcou, Harriet Randolph Hyatt Mayor, A.S. Packard, Charles Schuchert, and Charles Walcott.

Records of Fairfield Academy and Fairfield Medical College, Herkimer County, New York, and the personal papers of Dr. William Mather, Alonzo C. Mather, Albert B. Watkins, and other families and individuals connected with the school and town.

Correspondence (1892-1960); diaries, genealogical materials, notebooks, photographs, printed material, including articles and clippings, scrapbooks, memorabilia, and sketchbooks. Correspondence includes that of Adelaide Cole Chase, Clara Carter Hyatt Coad, Anna Hyatt and Archer M. Huntington, Audella Hyatt, and Alfred G. Mayor.

Writings, diaries, scrapbooks, correspondence, photo albums, memorabilia, typewriter of the American science fiction author.

Papers of the Romanian American artist, novelist, short story writer (1881-1960). Correspondence, diaries, drawings, manuscripts, photographs, sketches, memorabilia; includes some material relating to Neagoe's wife, painter and muralist Anna Neagoe.