If you watch newsreel footage of World War II American infantry troops in combat, you’ll no doubt see many non-commissioned officers (NCOs) carrying the Thompson submachine gun. Popularly known as the tommy gun it became a favored weapon of troops in close contact with the enemy. 

Well-made and packing a powerful punch with the .45 ACP cartridge, the Thompson had a lot more firepower than any of the other submachine guns of its era that fired the 9mm cartridge. It was used from the 1920s by both law enforcement and American gangsters. In saw use all the way up to 1989’s Operation Just Cause invasion of Panama, when some troops from the 7th Special Forces Group carried the iconic weapon into combat in the invasion of Panama.

We Need a Trench Broom

The Thompson Submachine Gun, a WWII and Gangster Icon
A police-issue Thompson SMG with forward pistol grip, drum magazines, and carrying case, circa 1920s.

The Thompson submachine gun was first designed by John Thompson in 1918. He was looking for a “one-man, hand-held machine gun” in .45 ACP as a “trench broom” for use in the bloody trench warfare of World War I. 

“Our boys in the infantry, now in the trenches, need a small machine gun, a gun that will fire 50 to 100 rounds, so light that he can drag it with him as he crawls on his belly from trench to trench, and wipe out a whole company single-handed,” Thompson wrote during the war. “I want a little machine gun you can hold in your hands, fire from the hip, and reload in the dark. You must use ammunition now available and I want it right away.”

The Thompson Submachine Gun, or Tommy Gun, a WWII and Gangster Icon
The tommy gun was favored by gangsters in the 1920s as it would fit in a violin case.

Thompson set up Auto-Ordnance Corporation to start manufacturing the gun. Among his hires were Theodore Eickhoff and Oscar Payne who were instrumental in designing the gun. Payne designed the weapon to be able to utilize both box and drum magazines. The prototype weapon was named the “Annihilator I.” However, the war ended before the weapons could find their way into the hands of the American troops in France.

Thompson then set out to market the tommy gun to civilian law enforcement agencies, which bought it in respectable quantities. The American underworld also became enamored with the Thompson, as civilians could purchase one for the sum of $200 (about $3,000 in today’s value.) 

Perhaps the most infamous use of the weapon was during the St. Valentine’s Day Massacre in Chicago. It was during this time that the tommy gun acquired a slew of other nicknames among them, “Chicago Typewriter,” “Chicago Submachine,” “Chicago Piano,” “Chicago Style,” “Chicago Organ Grinder,” “Drum Gun,” or “the Chopper.”

A small amount of the weapons were sold to the U.S. Postal Service and U.S. Marine Corps which favored the weapon in the Banana Wars in Central America and China.