government-issue M1911 and M1911A1 pistols
Following its success in trials, the Colt pistol was formally adopted by the Army on March 29, 1911, when it was designated Model of 1911, later changed to Model 1911, in 1917, and then M1911, in the mid-1920s. The Director of Civilian Marksmanship began manufacture of M1911 pistols for members of the National Rifle Association in August 1912. Approximately 100 pistols stamped “N.R.A.” below the serial number were manufactured at Springfield Armory and by Colt.[12] The M1911 was formally adopted by the U.S. Navy and Marine Corps in 1913.

World War II and the years leading up to it created a great demand. During the war, about 1.9 million units were procured by the U.S. Government for all forces, production being undertaken by several manufacturers, including Remington Rand (900,000 produced), Colt (400,000), Ithaca Gun Company (400,000), Union Switch & Signal (50,000), and Singer (500). New M1911A1 pistols were given a parkerized metal finish instead of blueing, and the wood grip panels were replaced with panels made of brown plastic. The M1911A1 was a favored small arm of both US and allied military personnel during the war, in particular, the pistol was prized by some British commando units and Britain’s highly covert Special Operations Executive, as well as South African Commonwealth forces.