The 18th Amendment banned alcohol production and sale in the US, taking effect in 1920. The Volstead Act defined intoxicating liquor as over 0.5% alcohol to enforce Prohibition. Supporters wanted to improve morality and health, but it instead increased crime and corruption. Organized crime grew through bootlegging and speakeasies. Prohibition failed economically, politically, socially and culturally. It was repealed in 1933 with the 21st Amendment due to widespread opposition and its ineffectiveness.