The roaring 20's in early 20th century America was a period of mass consumerism marked by general feelings of novelty associated with modernity and a break with tradition. Jazz boomed and flapper girls were all the rage. But the 1920s were not merely marked by gaiety and partying, but also prohibition, the prevention of the sale of alcohol.
During the 19th century, alcoholism-induced family violence and saloon-based political corruption prompted prohibitionists to begin fighting to end the sale of alcohol as a means of curing society.
At first, prohibition gained a national grassroots base through the Woman's Christian Temperance Union. After 1900, it was coordinated by the Anti-Saloon League.
Despite opposition from "wet" supporters, "dry" supporters (as Prohibitionists were known as) continually petitioned for alcohol consumption to be made illegal, and they're hard work paid off. The brewing industry was slowly shut down in state after state by state legislatures before being nationally shut down by the Eighteenth Amendment to the United States Constitution, which was passed in 1920.
The Prohibitionists achieved their goal and alcohol consumption has significantly hampered as a result. However, the method that the federal government employees to achieve such a sharp decrease in the consumption of alcohol is not as one would expect. Rather than trying to dissuade drinking through fines and imprisonment, the government poisoned the alcohol that was still legal. Pretty extreme, but undoubtedly effective. Such a potentially life-threatening punishment would convince any sane person to give up alcohol. Luckily, prohibition was ended thanks to the Twenty-first Amendment to the United States Constitution. Now people can drink their beer without fear of poisoning (from things other than alcohol poisoning from overconsumption).