The Pentagon 3,460 recipients of the Medal of Honor, the United States' highest military decoration. The Hall is also used for promotions, retirements, and other ceremonies. Notes Bibliography 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
Arlington County, Virginia county having the same name, a movement started to rename Alexandria County. In 1920, the name Arlington County was adopted, after Arlington House, the home of the American Civil War Confederate general Robert E. Lee, which stands on the grounds of what is now Arlington National Cemetery. The Town of Potomac was incorporated as a town in Alexandria County in 1908. The town was annexed by the independent city of Alexandria in 1930. In 1896, an electric trolley line was built from Washington through Ballston, which led to growth in the county (see Northern Virginia trolleys). In 1920, the Virginia