Longitude west from Washington, D.C. Stated on map: "Designed and constructed under the orders of Postmaster General Marshall Jewell and Second Assistant Postmaster General James N. Tyner….", 56 x 40 inches
Nicholson, W. L. (Topographer) (1876). Post route map of the state of Minnesota. Post Office Dept.; Washington, D.C.?. https://umedia.lib.umn.edu/item/p16022coll247:269 (map)