Because of the gun violence in the U.S. in the 1930s that was related to the mob over Prohibition and the control of illegal liquor sales in Speak Easy's, Congress passed the Gun Control Act of 1934.
This gave rise to the BATF and the control of fully automatic weapons.
I know machine Gun Jack McGurn is laughing up his sleeve right now over this craziness. McGurn was Al Capone's body guard.
At a Cub's game he was sitting behind Capone. Something spooked him and he was reaching inside his jacker for the Colt 1911 auto in his shoulder holster. That picture was in the Chicago Tribune.
McGurn was a lefty. One of those guys on the Chicago Outift Facebook page said, "They only forced people to be right handed in Catholic schools. Jack didn't have a lot of schooling." ;)