Beer in the United States
On January 16, 1919, the Eighteenth Amendment to the United States Constitution was enacted into law, creating the Prohibition era, wherein the production, sale and transportation of alcoholic beverages was made illegal. All legal American brewing came to a halt when prohibition was imposed, though the earlier temperance movement had already reduced the number of breweries significantly. Only a few breweries, mainly the largest, were able to stay in business by manufacturing near beer, malt syrup, or other non-alcohol grain products, in addition to soft drinks such as colas and root beers. Production and shipping of alcohol was largely confined to illegal operations that could deliver compact distilled beverages—smuggled rum and domestic moonshine—more efficiently and reliably than bulkier products such as beer.
Progressive Era
By 1917, two thirds of the states had some form of prohibition laws and roughly three quarters of the population lived in dry areas. In 1913, the Anti-Saloon League first publicly appealed for a prohibition amendment. They preferred a constitutional amendment over a federal statute because although harder to achieve, they felt it would be harder to change. As the United States entered World War I, the Conscription Act banned the sale of liquor near military bases. In August 1917, the Lever Food and Fuel Control Act banned production of distilled spirits for the duration of the war. The War Prohibition Act, November, 1918, forbade the manufacture and sale of intoxicating beverages (more than 2.75% alcohol content) until the end of demobilization.