The M1911 (also called Automatic Colt Pistol [ACP] or Colt 45) was the pistol of the United States Armed Forces for 74 years, from 1911 to 1985. Civilian models and most models delivered to the American forces were manufactured by the Colt's Patent Fire Arms Manufacturing Company, in Hartford, Connecticut. The M1911 is one of the few weapons to have been massively used in both World Wars.