Map of N. Eastern Virginia and vicinity of Washington : surveys for military defenses / compiled at Topographical Engineers office at Division headquarters ofGeneral Irvin McDowell.United States. Army. Corps of Engineers1862"Arlington, January 1st 1862 from published and manuscript maps corrected by recent Surveys and Reconnaissances.""Engraved on stone by J. Schedler No. 120 Pearl St. N.Y."Includes table of "Elevations above tide water", "Geological profile of Loudoun Coucartographic