Professor. Personal correspondence (1897-1957); correspondence with Campbell's relatives (1822-1896); correspondence with publishers and literary agents (1920-1958); literary manuscripts (ca. 1914-1957); diaries, notebooks, and journals...
Author. Correspondence (ca. 1923) regarding the Benders of Kansas, and the genealogy of families in Big Sandy Valley, Kentucky; notebooks (ca. 1854-1913) concerning the Civil War, William Quantrill, Indians, linguistics, border wars, Kansas history...