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
Construction of the Virginia approaches to Arlington Memorial Bridge begin construction, but it ended after the county election in November 1931 left supervisors safe in office for another two years. Arlington County engineers quickly called the Washington Boulevard route south of the cemetery inappropriate. The Washington Boulevard route received a significant boost when, on January 27, 1933, Arlington County, the NCPC, and the United States Department of War reached an agreement on rights-of-way along the route. The agreement gave the county a right-of-way across Fort Meyer and the southwestern tip of Arlington National Cemetery and another right-of-way from the cemetery to Mount Vernon Memorial Parkway across War Department land.