designed and constructed under the orders of Postmaster General Wm. Dennison and Second Ass't Postmaster Gen'l Geo. Wm. McLellan, by W.L. Nicholson topographer of P.O. Dept. ; drawn by P. Goepel ; eng. by D. McClelland.
Prime meridian: Washington, D.C.
Includes a table of distances and a table of general statistics for 1860 and 1866.
"The service on this diagram brought up to date of March 1st 1874."