The John R. Williams papers contain correspondence and financial documents related to supplies for United States army troops at Fort Massac and Cantonment Wilkinsonville, on the Ohio River. Also included are documents and financial records related to Williams's mercantile business, based in Detroit, Michigan.
The Correspondence series comprises the bulk of the collection, and includes both incoming and outgoing letters related to the contract agent's work supplying garrisons at Fort Massac and Cantonment Wilkinsonville. Most items are official letters concerning military supplies, including correspondence from Oliver Ormsby and copies of outgoing letters written by John R. Williams. Two personal letters are a French-language letter Williams wrote to his uncle, Joseph Campau (July 24, 1800), and P. McNiff's letter challenging Williams to a duel (October 5, 1800). Williams wrote a brief note to Colonel David Strong stating the army's intention to cede the Wilkinsonville post to Native Americans (April 10, 1801). Two undated letter drafts, which Williams composed in French, discuss the author's army service and his desire to remain in Detroit.
The Receipts and Contracts series (52 items) contains material related to supplies for troops stationed at Fort Massac and Cantonment Wilkinsonville (1798-1801) John R. Williams's business affairs in Detroit, and to John R. Williams's business affairs in Detroit (1805-1816). Inventories, Invoices, and Reports concern supplies at Cantonment Wilkinsonville. The Miscellaneous series is comprised of 2 French-language items; one is a prayer entitled "La Journée Chrétienne."