Prohibition (1919-1933). The name stemmed from the hiding of full hipflasks in the legs of boots.
In 1919, the Volstead Act was passed in America, prohibiting the sale, purchase, production and consumption of all alcohol. It was subverted from the second it went into effect, and America consumed an ocean of booze througout the 1920s.
Prohibition led to an unparallelled rise in organised crime, and the act had a significant effect on mortality rates – not simply through crime but also poisoned 'hooch' brewed in dirty, makeshift bathroom distilleries by bootleggers.