Arlington

Arlington county (1990 pop. 170,936), N Va., across the Potomac River from Washington, D.C. Arlington is a residential and commercial suburb of Washington. Within its boundaries are Arlington National Cemetery ; Arlington House, The Robert E. Lee Memorial ; the Pentagon ; the U.S. Marine Corps and Air Force memorials; Marymount Univ.; a campus of George Mason Univ.; and Ronald Reagan National Airport. Arlington has many federal facilities and major office developments as well as some industry, including printing and publishing, shipbuilding, and light manufacturing. Originally Alexandria County, Arlington was ceded to the federal government by Virginia in 1789 and was part of the District of Columbia until 1846, when it was returned to Virginia. In 1920 its name was changed to Arlington, after Robert E. Lee's home, Arlington House.

Arlington County in n Virginia, across the Potomac River from Washington, D.C. Since 1943 it has been the location of the Pentagon. The 200ha (500acre) Arlington National Cemetery (1864), built on the former estate of Robert E. Lee contains the Tomb of the Unknown Soldier, a memorial amphitheatre, and the graves of many servicemen and prominent Americans. Originally a part of the District of Columbia, it was made a county of Virginia in 1847. Pop. (2000) 189,453.

Naval Sea Systems Command NAVSEA the largest of the Navy's five systems commands, its engineers build and support U.S. ships and combat systems, and serve in four shipyards, in undersea and surface warfare centers, and at major shipbuilding sites. Its headquarters is at Crystal City, Arlington, Virginia.