The United States Armed Forces are the overall unified military forces of the United States. The United States military was first formed by the second Continental Congress to defend the new nation against the British Empire in the American Revolutionary War. The Army, Marine Corps, and Navy were commissioned in 1775, in anticipation of the declaration of independence in 1776. The Coast Guard originated as the Revenue Cutter Service, which was formed in 1790. The Revenue Cutter Service merged with the United States Life-Saving Service in 1915 to become the Coast Guard, now an agency of the Department Homeland Security and can be transferred to the Department of the Navy by the President or Congress during a time of war. The United States Air Force originated as the United States Army Air Corps in 1926 and became an independent service in 1947. ---------------------- From the time of its inception, the military played a decisive role in the history of the United States. A sense of national unity and identity was forged out of the victorious Barbary Wars, as well as the War of 1812. Even so, the Founding Fathers were suspicious of a permanent military force and not until the outbreak of World War II did a peacetime army become officially established. The President is commander-in-chief of the military, with the Department of Defence, headed by the Secretary of Defence, as the principal organ by which military policy is carried out. The 11 September attacks prompted the formation of a new civilian agency, the Department of Homeland Security, to coordinate and consolidate a counter on internal United States threats. -------------------- The U.S. military is composed of almost three million personnel, of which approximately half are reserve personnel. The U.S. military is one of the largest militaries in terms of number of personnel. The U.S. military draws its manpower from a large pool of volunteers and as such conscription is neither needed nor desirable as it maintains a purely professional military force. The U.S. military receives $711 billion per year in funding,constituting approximately 50 percent of world military expenditures. The U.S. armed forces as a whole possess large quantities of advanced and powerful equipment, which gives them significant capabilities in both defence and power projection.