 By the time of the Korean War in 1950, the Thompson had seen much use by the U.S. and South Korean military, even though the Thompson had been replaced as standard-issue by the M3/M3A1.With huge numbers of guns available in army ordnance arsenals, the Thompson remained classed as Limited Standard or Substitute Standard long after the standardization of the M3/M3A1.Many Thompsons were distributed to the US-backed Nationalist Chinese armed forces as military aid before the fall of Chiang Kai-shek's government to Mao Zedong's communist forces at the end of the Chinese Civil War in 1949 (Thompsons had already been widely used throughout China since the 1920s, at a time when several Chinese warlords and their military factions running various parts of the fragmented country made purchases of the weapon and then subsequently produced many local copies).