On January 16, 1919, the 18th Amendment to the Constitution was ratified in the United States by the Volstead Act: it prohibited "the production, sale and transportation of intoxicating liquors"; the Act came into force in 1920, thus initiating prohibition.
In fact, local laws prohibiting the production of alcohol had been introduced as early as 1905; this trend was due to a growing aversion to alcoholic beverages, embodied by the "temperance movement", the movement for sobriety. This was a widespread international trend that had begun to take hold in the United States as early as the nineteenth century. It promoted abstinence from alcohol as part of a moral and virtuous lifestyle: alcohol, it was claimed, was to blame for various social problems, including high crime and unemployment rates. Consequently, its production and consumption had to be restricted or banned. Women were an important component of this movement: as the main breeders and educators of children at the time, they claimed to have the right and the duty to encourage virtuous behaviour.
During prohibition, however, the consumption of liquor did not stop: the outlawing of the law led to the development of "bottleging" (the illegal manufacture and sale of beverages) and led to the creation of "speakeasies", the premises where alcohol was bought and drunk illegally. All this contributed to make organized crime richer, which managed to gain an important space within this underground business.
During the Twenties and the early Thirties, therefore, support for prohibition gradually decreased, also because it was considered a limitation to personal liberties.
It did not end until 1933, when the 21st amendment repealed the 18th amendment and again restricted the production and consumption of alcohol.