The United States Marine Corps (USMC), also referred to as the United States Marines, is the maritime land force service branch of the United States Armed Forces responsible for conducting expeditionary and amphibious operations through combined arms, implementing its own infantry, artillery, aerial, and special operations forces. The U.S. Marine Corps is one of the eight uniformed services of the United States.
The Thompson submachine gun was widely adopted by the U.S. armed forces during World War II, and was also used extensively by other Allied troops during the war. Its main models were designated as the M1928A1, M1 and M1A1 during this time. More than 1.5 million Thompson submachine guns were produced during World War II.