At the stroke of midnight on 16 January 1920 the US went dry. For the next 13 years Prohibition made it illegal to buy or sell alcohol.
Yet rather than discouraging drinking, it had quite the opposite effect. Thousands of illegal drinking dens opened. The "Roaring Twenties" had begun. The capital of all this hedonism was Atlantic City in New Jersey - a Las Vegas before Vegas was even invented.
Prohibition had another spin-off: it provided a bonanza for Italian, Irish and Jewish street gangs who came to control the supply and distribution of alcohol. It became a multimillion-dollar business and gave birth to the modern Mafia.