1. The 18th Amendment to the Constitution, or "Liquor prohibition amendment," was proposed by Congress on December 18, 1917, and ratified January 16, 1919. It called, one year from ratification, for the prohibition of the manufacture, sale, or transportation of intoxicating liquors within, the importation thereof into, or the transportation thereof from the United States and its territories. It took effect January 16, 1920.

Prohibition has been referred to by subsequent historians as "America's most unpopular law" and one that helped give rise to organized crime in America. It also fueled the wild times that became known as the "Roaring 20s".