The United States Marine Corps is one of the service branches of the United States Armed Forces. Its primary role is to provide force projection from the sea, often in cooperation with the United States Navy. In addition to amphibious operations, the Marine Corps can also serve a more general combat role in military expeditions overseas and provide security for American embassies, consulates, and American naval installations. The United States Marine Corps has strong ties to the Navy and is part of the United States Department of the Navy, but has its own separate military command structure. Its highest ranking officer is the commandant of the Marine Corps, a four-star general and a member of the Joint Chiefs of Staff.
The modern United States Marine Corps focuses on amphibious capability, combined arms tactics, and the ability to deploy expeditionary forces abroad on short notice. It is a lighter force than the United States Army, with a smaller proportion of troops in support roles and a greater emphasis on infantry. The Marine Corps makes extensive use of close air support provided by attack helicopters, fixed-wing attack aircraft launched from land or from aircraft carriers, and vertical take-off and landing (VTOL) airplanes, such as the Harrier ground attack aircraft, which can launch from amphibious assault ships without requiring a runway.
A United States Marine Corps operation is usually structured around an organization called a Marine Air-Ground Task Force (MAGTF). A MAGTF is a combined arms force under a single overall commander. They vary in size according to their mission, but each MAGTF has its own headquarters, ground and aviation combat, and logistics elements. The largest type of MAGTF is called a Marine Expeditionary Force, a somewhat smaller unit is called a Marine Expeditionary Brigade, and the smallest MAGTFs are called Marine Expeditionary Units.
The United States Marine Corps has several specialized subdivisions. The Marine Corps Security Force Regiment is charged with protecting naval installations and has specialized anti-terrorist teams that can be quickly deployed during unexpected crisis situations. The Marine Corps Embassy Security Group protects American embassies, consulates, and government offices in foreign countries. Headquarters Marine Corps, which serves primarily staff and administrative functions, includes the commandant and agencies such as Marine Aviation, the Intelligence Department, and Marine Corps Logistics Command.
The forerunners of the United States Marine Corps were the Continental Marines, formed during the Revolutionary War by order of the Continental Congress on 10 November 1775. They served as security forces and sharpshooters on the ships of the Continental Navy. They also fought in ground battles and amphibious assaults, including a raid on British naval facilities in the Bahamas. They were disbanded along with the Continental Navy in 1783. In 1797, the US government began recruiting Marines to serve on the ships of the recently established United States Navy, and the United States Marine Corps was officially established by an act of Congress in 1798.