This primary source comes from the Records of the Office of the Chief of Engineers.
Full Citation: Map of North America; 1826; United States; Civil Works Map File, 1818 - 1947; Records of the Office of the Chief of Engineers, Record Group 77; National Archives at College Park, College Park, MD. [Online Version, https://docsteach.org/documents/document/map-of-north-america-1826, April 18, 2024]