Keenan's manuscripts include the following: Salt in the Coffee, The Burden Light, The History of the St. Paul Seminary, Hush Money, Jacophon, John Mask, Lincoln, and Dew Drop Inn. The autograph collection includes signatures of: Nowell Coward, Lynn Fontaine, Charles Lawton, Thomas De Quincey, John Jacob Astor, William Wordsworth, Oscar Wilde, Thomas Carlyle, Matthew Arnold, Samuel T. Coleridge, Robert Browning, Dante Gabriel Rossetti, William Jennings Bryan, and William M. Thackeray. Keenan's theatre program collection includes over two hundred items, representing plays seen between 1920 and 1967 in Minneapolis and St. Paul, New York, London, and elsewhere.