Type Submachine gun Place of origin United States Service history In service 1938–1971 (officially, U.S. military)1921–present (other countries) Wars Chaco WarBanana WarIrish Civil WarWorld War IIIndonesian National RevolutionChinese Civil WarFirst Indochina WarGreek Civil War1948 Arab–Israeli WarKorean WarAlgerian WarVietnam WarThe TroublesYugoslav WarsIraq Warand numerous … Continue reading M1921 Thompson submachine gun