“Enclosure VIII: Map of the Reserved Tract including Fort Chartres,” Founders Online, National Archives, https://founders.archives.gov/documents/Jefferson/01-18-02-0110-0022. [Original source: The Papers of Thomas Jefferson, vol. 18, 4 November 1790 – 24 January 1791, ed. Julian P. Boyd. Princeton: Princeton University Press, 1971, p. 215.]