Washington-Rochambeau Route-- Alexandria Encampment E-106). Most of the American and French armies set sail from three ports in Maryland--Annapolis, Baltimore, and Head of Elk--in mid-Sept. 1781 to besiege the British army in Yorktown. The allied supply-wagon train proceeded overland to Yorktown, its itinerary divided into segments called "Marches." Its "Fourth March" was from Georgetown to Alexandria; the wagons took two days, 24-25 Sept., to cross the Potomac and reunite in Virginia. The Alexandria camp was roughly a half-mile in area, located north of Oronoco Street and bisected by Washington Street. The train left Alexandria on 26 Sept. www.dhr.virginia.gov/hiway_markers/marker.cfm?mid=4064