The Thompson submachine gun was invented by John T. Thompson in 1918 with the intention of providing an automatic “trench-broom” to rid enemy troops from trenches during WWI, however the war ended before it could be distributed. Nicknamed “Tommy Gun”, “Annihilator”, and “Trench Broom” among others, it remains popular today due to its historical significance during the Prohibition Era and WWII.
The M1928 Thompson was the first version to be widely used by military forces. It had provisions for a box and drum magazine, but the latter proved to be heavy and noisy when used. The M1928 also featured a delayed blowback action and cooling fins on the barrel. However because the drum magazines were slow and heavy, the development of the M1 Thompson began in 1942 to further simplify the design.