The Appleton-Century mss., 1846-1962, consists of the office files of the publishing company, its two predecessors, D. Appleton & Co., and the Century Co., and to a small extent its successor, Appleton-Century Crofts, Inc.
The Armour mss., 1952-1956, consists of letters from author Upton Sinclair, 1878-1968, to author and English professor Richard Willard Armour, 1906-1989.
The Boni mss., 1926-1939, consists of the correspondence of author Upton Beall Sinclair, 1878-1968, with publishers Albert Boni, 1892-1981, and Charles Boni, 1894-1969.
The Cane mss., 1936-1957, consist of letters from Upton Sinclair, 1878-1968, author, to Melville Henry Cane, 1879-, lawyer and poet. They relate in the main to Sinclair's writings.
The Clark mss., 1909-1957, consists of the letters and writings of author, editor, and publisher Thomas Curtis Clark, 1877-1953, as well as the autographs and poems of other writers collected by him.
The Colorado-Sinclair mss. consists of letters exchanged between author, Upton Beall Sinclair, 1878-1968, and University of Colorado Director of Libraries Eugene Holt Wilson, 1909-?, Boulder, Colorado, August 25-October 31, 1950.
The DeWitt mss., 1941-1955, consists of letters from Upton Sinclair, 1878-1968, author, to Samuel Aaron DeWitt, 1891-1963, poet and businessman, and correspondence between Mary Craig (Kimbrough) Sinclair, (Mrs. Upton Sinclair), 1883-1961, and DeWitt.
The Eeden mss. consists of two reels, 1908-1913 and 1914-1918, of negative microfilm of letters and postcards of Upton Beall Sinclair, 1878-1968, novelist, to Frederik Willem van Eeden, 1860-1932, poet and dramatist, from the originals in the Frederik van Eeden-Genootschap at the University of Amsterdam in Amsterdam, Holland.
The Ehrmann mss., 1899-1926, consists of letters to Max Ehrmann, 1872-1945, author, from Eugene Victor Debs, Frank Harris and Upton Beall Sinclair, and Mrs. A. Schember.
The Engs, Ruth mss., 2001-2010, consist of typescripts, page proofs, correspondence, and research materials for works by health reform scholar Ruth Engs.
The Haldeman mss., 1948-1960, consists of files from Haldeman-Julius Publications of Girard, Kansas, containing correspondence with and book sales records of writer Upton Beall Sinclair, 1878-1968.
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 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 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 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 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 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.
The Kimbrough mss., 1961-1967, consists of the correspondence of bond salesman Hunter Southworth Kimbrough, 1900-1994, concerning his relationship with his brother-in-law, Upton Beall Sinclair, 1878-1968.
The Kus-Nikolajev mss., 1932-1957, are letters from Upton Beall Sinclair, 1878-1968, novelist, to Mirko Kus-Nikolajev, 1896-?, physician of Zagreb, Yugoslavia.
The Lesser mss., 1933-1971, consist chiefly of the correspondence between Sol Lesser, 1890-1980, motion picture executive, and Upton Beall Sinclair, 1878-1968, novelist, and others concerned with their interests.
The Lewisohn mss., 1922-1937, consist of letters from literary men to Ludwig Lewisohn, 1883-1955, author and critic, and personal letters from Lewisohn to his wife, Mrs. Thelma (Spear) Lewisohn, and her mother, Mrs. Elias Spear.
The Lush mss., 1956-1957, consists of two letters from Upton Beall Sinclair, 1878-1968, author, and a letter from Mrs. Mary Craig (Kimbrough) Sinclair, (Mrs. Upton Beall Sinclair), 1883-1961, author, to Samuel Beryl Lush, 1893?-?, cotton merchant.
The Nikolaevskiî mss., 1938-1944, are letters and papers extracted from books collected by Boris Ivanovich Nikolaevskiî, 1887-1966, Russian revolutionary and author.
The Saturday Review of Literature mss., 1946-1956, consists of letters from author Upton Sinclair, 1878-1968, to Norman Cousins, 1915-1990, and Harrison Smith, 1888-1971, editors of the Saturday Review of Literature.
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 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. 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 Sinclair mss. VIII, 1939-1998, consist of financial documents, correspondence, and contracts from McIntosh & Otis during their representation of Upton Sinclair and the Sinclair estate through David Sinclair.
The Singer, D. mss., 1948-1965, consist of letters and notes to, from, and about author Upton Beall Sinclair, 1878-1968, collected by educator Donald Lee Singer, 1936-.
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 Stone mss., 1888-1965, are the papers of Meta (Fuller) Stone. They consist of her writings, including an autobioraphical novel and poetry, and her correspondence with her friends and with her (ex-)husband Upton Beall Sinclair, 1908-1917, much of it concerned with her divorce.
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.
This collection consists of articles written by Upton Sinclair between the years 1905 and 1929, published in various magazines, newspapers, and journals.
This collection consists of articles written by Upton Sinclair between the years 1930 and 1939, published in various magazines, newspapers, and journals.
This collection consists of articles written by Upton Sinclair between the years 1940 and 1961, published in various magazines, newspapers, and journals.
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.
The Viereck mss., 1943-1953, consists of typescripts of letters from novelist Upton Beall Sinclair, 1878-1968, to Peter Robert Edwin Viereck, 1916-2006, author and professor of history at Mount Holyoke College.