The Thompson submachine gun is an American submachine gun, invented by John T. Thompson in 1918, that became infamous during the Prohibition era. It was a common sight in the media of the time, being used by both law enforcement officers and criminals. The Thompson submachine gun was also known informally as the “Tommy Gun”, “Annihilator”, “Chicago Typewriter”, “Chicago Piano”, “Chicago Style”, “Chicago Organ Grinder”, “Trench Broom”, “Trench Sweeper”, “The Chopper”, and simply “The Thompson”.
The Thompson was favored by soldiers, criminals, police, and civilians alike for its large .45 ACP cartridge, accuracy, and high volume of automatic fire. It has since gained popularity among civilian collectors for its historical significance. It has had, and continues to have, considerable significance in popular culture, especially in works about the U.S.’s Prohibition era and World War II, and hence is among the best-known firearms in recent history. Although the original fully automatic Thompsons are no longer produced, numerous semi-automatic civilian versions are still being manufactured by Auto Ordnance. These retain a similar appearance to the original models, but they have various modifications in order to comply with US firearm laws.