The Volstead Act (National Prohibition Enforcement Act), passed on October 28, 1919, provided for enforcement of the recently ratified Eighteenth Amendment, which prohibited the manufacture, sale, or transportation of alcoholic beverages in the United States. The act, passed over President Woodrow Wilson's veto, affirmed and further specified the provisions of the Eighteenth Amendment, delineated fines and prison terms for violation of the law, empowered the Bureau of Internal Revenue to administer Prohibition, and classified as alcoholic all beverages containing more than one-half of 1 percent alcohol by volume.
The temperance movement had been active in the United States for most of the nineteenth century and since 1900 had placed increasing emphasis on legal prohibition rather than personal reform. By 1914, fourteen states had adopted prohibition; by 1919, the number had risen to twenty-six. Even many temperance advocates had opposed the extension of federal power necessarily involved in national prohibition, but with the outbreak of World War I, the Anti-Saloon League was able to win passage of various federal prohibitory laws as part of the war effort, either to protect the morals of servicemen or to conserve grain for nutritional purposes. Thus, the principal effect of the Volstead Act was to extend the wartime measures to peacetime.
Once passed, Prohibition proved extraordinarily difficult to enforce. Although overall drinking was generally thought to have declined, it continued uninterrupted in many parts of the country, particularly in large cities and in areas with large foreign-born populations. Critics pointed to the demoralizing effect of a law that was routinely violated by respectable citizens and maintained that the profitable business of supplying illegal liquor fostered the growth of organized crime and the corruption of public officials.
Calls for repeal of the Eighteenth Amendment began as early as 1923. Republicans continued to defend the "experiment noble in purpose" (as President Herbert Hoover called it), but division over the issue nearly sundered the Democratic party in 1928. An investigation ordered by Hoover in 1929 and completed in 1931 confirmed that the Eighteenth Amendment remained largely unenforced. In 1932, the Democrats came out for repeal of Prohibition. Their overwhelming electoral victory encouraged Congress to pass the Twenty-first Amendment, repealing the Eighteenth, on February 20, 1933. On March 22, the Volstead Act was amended to permit the sale of 3.2 percent beer and wine. Once the Twenty-first Amendment was ratified the following December, the Volstead Act became void.