The Eighteenth Amendment was ratified on January 16, 1919, the result of years of advocacy by the temperance movement. The subsequent passage of the Volstead Act established federal enforcement of the nationwide prohibition on alcohol. As many Americans continued to drink despite the amendment, Prohibition gave rise to a profitable black market for alcohol, fueling the rise of organized crime. Throughout the 1920s, Americans increasingly came to see Prohibition as unenforceable, and a movement to repeal the Eighteenth Amendment grew until the Twenty-first Amendment was ratified in 1933.