The United States Navy, founded in 1798, is one of the armed forces service departments in the United States Department of Defense. Headquartered in Washington, D.C., the Navy department maintains, trains and equips combat-ready naval forces. It has more than 340,000 active duty personnel, over 270 deployable battle force ships and nearly 4,000 aircrafts. The department s military sealift command operates more than 110 ships worldwide. Its aircraft carriers allow the mobile projection of Naval Air Power across the globe. The department has a large fleet of amphibious assault ships that deploy and support the United States ground forces in remote locations. It is a part of the Department of Defense, which offers a wide range of services, including war fighting, humanitarian aid, peacekeeping, disaster relief and homeland security.