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
U.S. Route 50 in the District of Columbia U.S. Route 50 in the District of Columbia U.S. Route 50 (US 50) is a major east–west route of the U.S. Highway system, stretching just over from Ocean City, Maryland, on the Atlantic Ocean, to West Sacramento, California, nearly to the Pacific Ocean. In the District of Columbia, US 50 passes between Arlington County, Virginia, and Prince George's County, Maryland, predominantly along surface streets, including a part of Constitution Avenue along the National Mall. US 50 enters the District of Columbia from Arlington, Virginia, merging with I-66 on the Theodore Roosevelt Bridge over the Potomac River. US 50 traffic exits