The Pentagon The Pentagon The Pentagon, in Arlington County, Virginia, across the Potomac River from Washington, D.C., is the headquarters of the United States Department of Defense. As a symbol of the U.S. military, the phrase "The Pentagon" is often used as a metonym for the Department of Defense and its leadership. The building was designed by American architect George Bergstrom and built by contractor John McShain. Ground was broken on September 11, 1941, and the building was dedicated on January 15, 1943. General Brehon Somervell provided the major motivating power behind the project; Colonel Leslie Groves was responsible for overseeing the
Arlington County, Virginia Arlington, most prominently the Antonin Scalia Law School of George Mason University. The area that now constitutes Arlington County was originally part of Fairfax County in the Colony of Virginia. Land grants from the British monarch were awarded to prominent Englishmen in exchange for political favors and efforts at development. One of the grantees was Thomas Fairfax, 6th Lord Fairfax of Cameron, who lends his name to both Fairfax County and the City of Fairfax. The county's name "Arlington" comes via Henry Bennet, Earl of Arlington, a Plantation along the Potomac River, and Arlington House, the family residence on that