The popularity of Thompson submachine guns with gangsters in the 1920s and 1930s led Congress to pass the National Firearms Act in 1934. The law required owners of fully automatic weapons to register them with the agency later known as the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF). Registration required a thorough background check and payment of a hefty tax.
This Tommy gun was hidden for decades in a house in Chicago. The initials “JM” carved into the stock have led some to believe it belonged to “Machine Gun” Jack McGurn, a close associate of Al Capone who is reputed to have planned the St. Valentine’s Day Massacre.