Map of the routes examined and surveyed for the Winchester and Potomac Rail Road, State of Virginia, under the direction of Capt. J.D. Graham, U.S. Top. Eng., 1831 and 1832; surveyed by Lts. A.D. Mackay and E. French, 1st Arty., assistants in 1831, and Lts. E. French and J.F. Izard, assistants in 1832; drawn from the original plot by Lt. Humphreys, 2d Artillery