U.S. Department of Defense

U.S. Department of Defense is America's oldest and largest government agency. Its mission is to provide the military forces needed to deter war and to protect the security of the country. The agency is not only in charge of the military, but also employs a civilian force of thousands. With over 1.4 million men and women on active duty, and 718,000 civilian personnel, it is the nation's largest employer. Another 1.1 million serve in the National Guard and Reserve forces. More than 2 million military retirees and their family members receive benefits. U.S. Department of Defense was founded in 1947 and is headquartered in Washington, District of Columbia.