The temperance movement convinced America to ban alcohol through the 18th Amendment, making it the only constitutional amendment later repealed. Starting in the 1820s, reformers like the Women''s Christian Temperance Union and the Anti-Saloon League blamed liquor for poverty, domestic violence, and crime. They targeted immigrants and urban workers, framing saloons as corrupting influences controlled by German brewers and Irish Catholics. By 1916, 23 states had banned alcohol. The movement''s pressure pushed Congress to pass the 18th Amendment in 1917, ratified by 46 states in just 13 months. Prohibition took effect January 17, 1920, outlawing the manufacture, sale, and transport of alcohol nationwide. The result: organized crime surged, federal agents seized millions of gallons of bootleg liquor, and Americans kept drinking anyway. After 13 years of corruption and violence, the 21st Amendment repealed Prohibition in 1933. The temperance movement showed how moral crusades can write their agenda into the Constitution—and how unpopular laws collapse under their own weight.