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, Kentucky on the name "Arlington" after Arlington Heights, Virginia, the hometown of a railroad official. The new city was incorporated in 1876. When Carlisle County was created in 1886, Arlington was initially selected as the seat of the new county. The nearby city of Bardwell challenged this, however, noting its more central location within the county. County officials agreed, and moved the seat to Bardwell shortly afterward. Arlington is located in southern Carlisle County at . U.S. Route 51 and Kentucky Route 80 intersect in the city. US 51 leads north to Bardwell, Kentucky, and to Cairo, Illinois, while leading south