Fort Monroe, SE Va., commanding the entrance to Chesapeake Bay and Hampton Roads; named for President James Monroe. The fortress (80 acres/32 hectares) was built (1819–34) by the U.S. government on the site of English fortifications erected in 1609 and 1727. Completely surrounded by a moat, the six-sided fort is the only one of its kind left in the United States. Fort Monroe was held by Union forces throughout the Civil War; Jefferson Davis, president of the Confederacy, was imprisoned there from 1865 until 1867. Long a U.S. army coast-artillery post and school, the fort was headquarters of the U.S. Army Training and Doctrine Command (TRADOC) from 1973 to 2011, when it was decommissioned as an active military installation. Fort Monroe was designated a national historic landmark in 1960 and a national monument in 2011.