Prohibition Law and Legal Definition

Prohibition in the United States between 1919 and 1933 was when the manufacture, transportation, import, export, and sale of alcoholic beverages was prohibited. Prohibition was enacted by passage of the Eighteenth Amendment, on January 16, 1920 when the Eighteenth Amendment went into effect. The Volstead Act was amended to allow "3.2 beer" (3.2 percent alcohol by weight, 4% by volume) by passage of the Blaine Act on February 17, 1933. The Eighteenth Amendment was repealed later that same year with ratification of the Twenty-first Amendment.

The 21st Amendment, which repealed nationwide prohibition, explicitly gives states the right to restrict or ban the purchase and sale of alcohol; this has led to a patchwork of laws, in which alcohol may be legally sold in some but not all towns or counties within a state.