The Coster mss., 1877-1938, consists of letters to Lincoln collector Robert Coster, 1851?-1928, relating to Lincoln, and letters to his nephew Paul Coster, relating to Lincoln and to John Sherman.
The Hambrecht mss., 1860-1940, consists of typewritten copies of correspondence of educator and Lincolniana collector George Philip Hambrecht, 1871-1943.
The Oldroyd mss., 1864-1909, are letters and papers of Osborn Hamiline Oldroyd, 1842-1930, Lincoln collector and museum curator, relating to the assassination of Abraham Lincoln.