Prohibition in the United States was a national ban on the sale, manufacture, and transportation of alcohol, in place from 1920 to 1933. The dry movement was led by rural Protestants in both political parties, and was coordinated by the Anti-Saloon League. The ban was mandated by the Eighteenth Amendment to the Constitution, and the Volstead Act set down the rules for enforcing the ban and defined the types of alcoholic beverages that were prohibited. Private ownership and consumption of alcohol was not made illegal. Prohibition ended with the ratification of the Twenty-first Amendment, which repealed the Eighteenth Amendment, on December 5, 1933.
The introduction of alcohol prohibition and its subsequent enforcement in law was a hotly debated issue. The contemporary prohibitionists presented it as a victory for public morals and health, but once the laws were passed they did little to help enforce them. The consumption of alcohol overall went down by half in the 1920s; and it remained below pre-Prohibition levels until the 1940s.
Anti-prohibitionists ("wets") criticized the alcohol ban as an intrusion of mainly rural Protestant ideals on a central aspect of urban, immigrant and Catholic everyday life. Effective enforcement of the alcohol ban during the Prohibition Era proved to be very difficult and led to widespread flouting of the law. The lack of a solid popular consensus for the ban resulted in the growth of vast criminal organizations, including the modern American Mafia, and various other criminal cliques. Widespread disregard of the law also generated rampant corruption among politicians and within police forces.