United States Department of Defense United States Department of Defense The Department of Defense (DoD, USDOD, or DOD) is an executive branch department of the federal government charged with coordinating and supervising all agencies and functions of the government concerned directly with national security and the United States Armed Forces. The department is the largest employer in the world, with nearly 1.3 million active duty servicemen and women as of 2016. Adding to its employees are over 826,000 National Guardsmen and Reservists from the four services, and over 742,000 civilians bringing the total to over 2.8 million employees. Headquartered at the Pentagon in Arlington, Virginia,
Arlington County, Virginia Arlington helps provide Catholic education in northern Virginia, with early learning centers, elementary and middle schools at the parish level. Bishop Denis J. O'Connell High School is the diocese's Catholic high school within Arlington County. Marymount University is the only university with its main campus located in Arlington. Founded in 1950 by the Religious of the Sacred Heart of Mary as Marymount College of Virginia, both its main campus and its Ballston Center are located on North Glebe Road, with a shuttle service connecting the two. George Mason University operates an Arlington campus in the Virginia Square area between Clarendon