This primary source comes from the Records of the Office of the Chief of Engineers.
Full Citation: A New Map of Our Country, Prospective and Present; 1856; 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://www.docsteach.org/documents/document/a-new-map-of-our-country-prospective-and-present, April 19, 2024]