The Thompson Submachine Gun, otherwise known as the "Tommy Gun", the "Chicago Typewriter", or the "Trench Sweeper", was created in 1919 by John T. Thompson. It features a large .45 ACP cartridge and an extremely high rate of fire, and it was favored by soldiers, criminals, and police alike.

When it was first released, it was available to the public, but sales were still relatively low. This is no surprise, considering that at $200 it cost half as much as a Ford Car.

The early model had a firing rate of 1,200 rounds per minute, quite amazing considering the fastest guns of the time fired at 850. This high firing rate had its drawbacks, though, as the gun tended to drift off of target. Later models of the weapon reduced the speed down to 600.