I've read many articles and reports that mentioned several things that impacted the rise of the Mafia, but rarely if ever is the Johnson-Reed Act brought up.

I think such a tough immigration law halted the migration of whichever group would have been the next up to arrive to America in droves. Their criminal element would have been brought here along with the majority of honest hardworking immigrants.

Might have caused problems for existing OC groups.


For a reference, this was during Prohibition (1920-33)