Navy Department

The United States Marine Corps was established on November 10, 1775, by resolution of the CONTINENTAL CONGRESS. The Marine Corps's composition and functions are detailed in 10 U.S.C.A. § 5063. Within the Department of the Navy, it is organized to include not less than three combat divisions and three aircraft wings, along with additional land combat, aviation, and other services. Its purpose is to provide forces necessary to seize or defend advanced naval bases and to conduct land operations essential to a naval campaign. In coordination with the U.S. Army and the U.S. Air Force, the Marine Corps develops the tactics, techniques, and equipment used by landing forces in amphibious (involving both sea and land) operations.

The Marine Corps also provides detachments and organizations for service on armed vessels of the navy, provides security detachments for the protection of naval property at naval stations and bases, and performs such other duties as the president may direct.

The Marine Corps is composed of the Marine Corps headquarters, the Operating Forces, and the supporting establishment. The Operating Forces consist of Fleet Marine Force Atlantic, Fleet Marine Force Pacific, Marine Corps Reserve, Marine Security Forces, and Marine Detachments Afloat. The supporting establishment includes recruiting activities, training installations, reserve support activities, ground and aviation installations, and logistics bases.

Basic combat units of the marines are deployed as Marine Air Ground Task Forces (MAGTFs). There are four types of MAGTFs: the Marine Expeditionary Force, the Marine Expeditionary Brigade, the Marine Expeditionary Unit, and the Special Purpose MAGTF. Each group has a command element, a ground combat element, an aviation combat element, and a combat service support element. Marine Expeditionary Forces are routinely deployed on amphibious ships to the Mediterranean Sea, Persian Gulf, and Pacific Ocean. Larger MAGTFs can rapidly deploy by air, sea, or any combination of means from both coasts of the United States and bases in the western Pacific to respond to emergencies worldwide.