The Haldeman mss. II, 1908-1951, consists of correspondence of writers and editors, including Emanuel Haldeman-Julius, 1889-1951, who were connected to Haldeman-Julius Publications.
The Keller mss., 1938-1953, consists of letters and copies of letters from novelist Upton Beall Sinclair, 1878-1968, to clergyman and professor of theology Adolf Keller, 1872-1963.
The Howatt mss., 1902-1959, consist in the main of letters to David Howatt, 1882-1964 , farmer and secretary of Upton Beall Sinclair, from writers Harry Kemp, Upton Beall Sinclair, and William James Durant.
The Haldeman mss. III, 1915-1918, consists primarily of correspondence of Upton Beall Sinclair, 1878-1968, novelist, and Appeal to Reason staff members Louis Kopelin, 1887-1949, and Walter H. Wayland, 1884-1980.
The Kelley mss., 1907-1935, consists of letters written by writer Sinclair Lewis, 1885-1951, to novelist Edith Summers Kelley, (Mrs. Clyde F. Kelley), 1883-1956.
