Prohibition was a period in U.S. history, between 1920 and 1933, when federal law forbade the manufacture, importation, or sale of alcohol. Brought on by a century-long temperance movement and effected by an amendment to the U.S. Constitution, Prohibition was an attempt by political and religious conservatives to solve what they believed to be the country’s social and economic problems. This ban on alcohol during the Prohibition era reduced the drinking of beer, wine, and liquor, but it also became a divisive political issue and helped a network of organized crime to become entrenched in America. Widespread opposition to the law caused its repeal in 1933.