The Haymarket Books mss., 1969-2010, consist of imprints produced by publisher Haymarket Books as well as issues of the International Socialist Review.
The Toyoshima mss., 1966-1998, consists of audio cassette tapes of interviews conducted by Joe Toyoshima in 1966 as an oral history of Upton Sinclair. Also included are materials related to the Industrial Workers of the World.
The Nikolaevskiî mss., 1938-1944, are letters and papers extracted from books collected by Boris Ivanovich Nikolaevskiî, 1887-1966, Russian revolutionary and author.
The Hunter, R. mss., 1923-1935, consist of the memoirs and letters of Robert Hunter, 1874-1942, sociologist, socialist, and Indiana University alumnus.
The Harris, L. mss. consists of materials related to the writing and publication of Upton Sinclair, American Rebel (Crowell, 1975), by author Leon A. Harris, 1926-2000.
The Fuchs mss., 1920-1979, consist of the correspondence, professional and teaching files, and writings of Ralph Follen Fuchs, 1899-1985, Indiana University Professor Emeritus of Law.
The Hapgood--Sacco-Vanzetti mss., 1920-1935, consists of letters written by shoemaker Nicola Sacco, 1891-1927, and fish peddler Bartolomeo Vanzetti, 1888-1927, while the two men were imprisoned in Massachusetts on the charge of murder.
The Curry mss., 1919-1945, primarily consists of the letters of socialist leader Eugene Victor Debs, 1855-1926 to his secretary Mabel (Dunlap) Curry, 1868-1947.
The Hapgood, M.D., mss., 1912-1975, consists of the correspondence and writings of Socialist leaders Mary Donovan Hapgood, 1886-1973, and Powers Hapgood, 1899-1949.