The M1911 is one of the most successful pistol designs in military history. Manufactured in the millions, the weapon was the standard personal defense weapon carried by officers and team leaders of all services during World War I, World War II, Korea and during the Vietnam conflict. It was very reliable and sturdy, the stopping power legendary. The stout mechanism is one of the strongest ever made. Mass production of the M1911A1 ended in 1945. The M1911 was the standard issue service pistol until 1984, when it began to be replaced by the M9 9mm pistol. Modified ‘fine tuned’ variants continue to serve with the Marine Corps and with Special Forces to this day.
John M. Browning designed the M1911 in response to the Army's need for a pistol with greater stopping-power following the Army's experience with close-in combat during the Philippine Insurrection of 1899-1901. Accounts abounded of the adversary, the dedicated and resourceful Moros, hacking to death multiple American soldiers or civilians before being killed themselves. Reputedly, the U.S. standard service small arms, the .30-caliber Krag-Jorgensen rifle—M1892 and M1896 models and .the 38 revolver was incapable of stopping brave yet suicide like Morro attackers. A public outcry tarnished the Army’s reputation. An indignant public and the U.S. Congress and wanted some answers. The slow moving gears at the Army quickened. The search for a replacement pistol began. Col. John T. Thompson (inventor of the Thompson sub-machine-gun) and a Col. Louis A. La Garde reached the conclusion that the army needed a .45" caliber cartridge, to provide adequate stopping power. In the mean time, the genius Browning, inventor of the BAR and the Thompson submachine gun, then employed at Colt, had already designed a successful automatic pistol capable of handling a large .45 cal cartridge. Browning re-engineered this handgun to accommodate a .45 caliber cartridge and submitted the pistol to the Army for evaluation. The weapon failed to pass the acceptance tests. Lessons learned, an improved prototype Browning pistol was re-submitted. The second time around, another Browning design impressively passed a grueling set of tests in 1911.
The Colt M1911 became the standard issue pistol for all branches of the U.S. military. Production was at first slow. Enough were manufactured to equip in part the US Army of WW1. As a result of battle experience an enhanced version, the 1911A1 model was adopted in 1926. The changes were not extensive and were confined to items involving the safety and mainspring housing.