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.
The Walker mss., 1912-1920, consists of the correspondence of socialist leader Eugene Victor Debs, 1855-1926, to cartoonist Ryan Walker, 1870-1932, and author Mrs. Maud Helena (Davis) Walker, (Mrs. Ryan Walker), 1870-1925.
The Sinclair mss. VI, 1907-1977, consists of correspondence, writings, and miscellaneous papers by and relating to author Upton Beall Sinclair, 1878-1968, his wife Mary Craig (Kimbrough) Sinclair, 1882-1961, and his son David Sinclair, 1901-1987.
The Lockhart, R. mss., 1906-1969, consist of the correspondence, writings and memorabilia of Sir Robert Hamilton Bruce Lockhart, 1887-1970, diplomat and writer.
The Lockhart, R. mss., 1906-1969, consist of the correspondence, writings and memorabilia of Sir Robert Hamilton Bruce Lockhart, 1887-1970, diplomat and writer.
The Stokes mss., 1905-1906, consist primarily of letters from Upton Beall Sinclair, 1878-1968, novelist, to James Graham Phelps Stokes, 1872-1960, regarding the activities of the Intercollegiate Socialist Society.
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 Sinclair mss. V, 1902, consists of the application of novelist Upton Beall Sinclair, 1878-1968, for a fellowship in the Graduate School of Harvard University for the year 1902-1903.
The Sinclair mss. IV, 1900-1963, consists of correspondence, writings, and monetary statements of author Upton Beall Sinclair, 1878-1968, and of his wife, Mary Craig (Kimbrough) Sinclair, 1883-1961.
The Trotskii mss., 1900-1957, consist principally of the correspondence of Lev Trotskii, 1879-1940, Russian communist leader, and Max Eastman, 1883-1969, author, during the period when Eastman was preparing his book about Trotskii in 1922 and 1923 and later when he served unofficially as Trotskii's literary agent from 1929 to 1933.
The Rogers, H.M. mss., 1895-1930, consist of letters from Booth Tarkington, 1869-1946, author, to Herbert Milton Rogers, 1870?-1931, lawyer, of Omaha, Nebraska, and former classmate of Tarkington at Princeton University.
The Overstreet mss., 1894-1985, consist of the correspondence, writings, lecture material, and memorabilia of married couple Harry Allen Overstreet and Bonaro Wilkinson Oversteet, who together wrote a bestselling book on Communism.
The Eastman mss. IV, 1890-2009, consist of the photographs, correspondence, personal papers, writings, and artwork of Max Eastman, 1883-1969; Yvette Szekely Eastman, 1912-2014; and Eliena Krylenko Eastman, 1895-1956.
The Amfiteatrov mss., 1890-1948, consists of the correspondence and writings of journalist and playwright Aleksandr Valentinovich Amfiteatrov, 1862-1938.
The Eastman mss. V, 1880-2009, consist of the photographs, correspondence, personal papers, writings, and legal documents of Max Eastman, 1883-1969; and Yvette Szekely Eastman, 1912-2014.
The Indiana History mss., 1725-1973, consists of individual items related to the history of the state of Indiana, acquired separately either as a gift, purchase, transfer, or removal from a variety of sources.
The U.S. History mss., 1612-1977, consist of individual items acquired separately either as a gift, purchase, transfer, or removal from a variety of sources, relating to the United States. Additions continue to be made.