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Tommy Gun

The Tommy Gun is a common nickname for the Thompson submachine gun, an American selective-fire submachine gun developed by John T.

By Ethan Anderson| Reviewed by Olivia Bennett, Standards & Fact-Checking Lead| Updated July 26, 2026|2 min read| Fact-checked

The Tommy Gun is a common nickname for the Thompson submachine gun, an American selective-fire submachine gun developed by John T. Thompson in the late 1910s. It became widely known for its use by U.S. forces, law enforcement, and organized crime during the Prohibition era, and later saw extensive service in World War II.

Design and development

The Thompson submachine gun was developed in the United States by John T. Thompson as a short-range, rapid-firing weapon. It was designed around the idea of a portable automatic firearm for close combat, especially trench warfare.

Use in crime and law enforcement

During the Prohibition era, the Tommy Gun became closely associated with gangsters, bank robbers, and violent organised crime. It was also used by police and federal agents, contributing to its notoriety in American public culture.

Military service

Although it did not become a standard U.S. Army issue weapon in World War I, the Thompson later saw substantial use in World War II. Its durability and firepower made it useful in close-quarters fighting.

Cultural legacy

The Tommy Gun became one of the most recognisable firearms of the 20th century and entered popular culture under names such as “Chicago typewriter.” Its image is strongly tied to gangster films, Prohibition history, and wartime photography.

Key facts

  • The term “Tommy Gun” refers to the Thompson submachine gun.
  • It was developed by Brigadier General John T. Thompson in the late 1910s.
  • The weapon became especially associated with gangsters and organized crime in the 1920s and 1930s.
  • It was also used by military and law-enforcement personnel, especially during World War II.
  • The Thompson was chambered in .45-calibre ammunition and used drum or box magazines.
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Canadian context

The Tommy Gun is part of broader North American firearms and crime history, and it is often referenced in Canadian museum collections, war history, and popular culture discussions of 20th-century firearms.

Frequently asked questions

What is a Tommy Gun?
A Tommy Gun is a nickname for the Thompson submachine gun, an American automatic firearm developed in the late 1910s.
Who invented the Tommy Gun?
It was developed by Brigadier General John T. Thompson, an American Army officer.
Why is it called the Tommy Gun?
“Tommy Gun” became a popular colloquial name for the Thompson submachine gun, alongside “Chicago typewriter” and “trench broom.”
What cartridge did it use?
The Thompson was chambered in .45-calibre ammunition, commonly .45 ACP.
Why is it associated with gangsters?
It became widely publicised during U.S. Prohibition, when it was used in violent criminal incidents and gang warfare.

References

  1. Wikipediahttps://en.wikipedia.org/wiki/Thompson_submachine_gun
    Supports: Nickname, development date, designer, action type, and alternate names.
  2. Encyclopaedia Britannicahttps://www.britannica.com/technology/Thompson-submachine-gun
    Supports: Designer, ammunition, magazines, Prohibition-era notoriety, and historical context.
  3. Popular Mechanicshttps://www.popularmechanics.com/military/weapons/a25414/tommy-gun-thompson-submachine/
    Supports: Popularity in popular culture, wartime service, and nickname usage.
  4. Warfare History Networkhttps://warfarehistorynetwork.com/thompson-guns-curious-history-from-world-war-i-to-world-war-ii/
    Supports: Origins as a World War I trench weapon and development history.
  5. Coffee or Diehttps://www.coffeeordie.com/article/tommy-gun
    Supports: Broad historical use by military, law enforcement, and criminals.