When federal Prohibition finally arrived, it was disguised as a program of wartime austerity. In 1917, as the country entered the First World War, Congress banned distillation, in order to conserve food, and restricted the grain available to brewers, eventually limiting their beer to no more than 2.75 per cent alcohol. These measures helped make Prohibition seem both feasible and patriotic, especially since the brewers who supplied the saloons were largely German-American. No less important, the Sixteenth Amendment, adopted in 1913, established a national income tax; until then, as much as thirty per cent of federal revenue had come from excise taxes on alcohol.
Kelefa Sanneh, “Drunk With Power” The New Yorker (21 & 28 December 2015), 107.