The Eighteenth Amendment

The Eighteenth Amendment prohibited the manufacture, sale, or transportation of intoxicating liquors within, the importation thereof into, or the exportation thereof from the United States for beverage purposes, beginning one year after ratification. It gave Congress and the states concurrent power to enforce it. Ratified on January 16, 1919, it took effect on January 17, 1920. It was the culmination of a century-long temperance movement led by groups such as the Woman's Christian Temperance Union and the Anti-Saloon League, and the first amendment to include a ratification deadline.

Congress passed the National Prohibition Act, known as the Volstead Act, over President Woodrow Wilson's veto in 1919, defining intoxicating liquor as any beverage with more than 0.5 percent alcohol. Enforcement fell to a Prohibition unit in the Treasury Department, later the Bureau of Prohibition, which was understaffed for the scale of the task. Illegal speakeasies, bootlegging, and organized crime flourished, though alcohol consumption did decline, and enforcement strained federal courts and prisons.

Support for Prohibition eroded during the 1920s and collapsed in the Great Depression, as repeal advocates argued it bred crime and disrespect for law and that legal alcohol would bring jobs and tax revenue. The Twenty-first Amendment repealed it on December 5, 1933, the only time an amendment has been repealed. Its legacy includes the expansion of federal law enforcement, the agencies that became today's alcohol and firearms regulators, and a lasting debate over using the Constitution to settle social policy.