The United States Army adopted the Colt-Browning .45 Automatic as the U.S. Pistol, Automatic, Caliber .45, Model 1911 on March 29, 1911. Between the date of its adoption and its official replacement in 1985, the M1911 served in World War I, World War II, the Korean War, and the Vietnam War.
While no longer the primary sidearm of the U.S. armed forces, 1911-pattern pistols remain popular among private citizens for self-defense, competitive target shooting, and collecting.