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.