Prohibition was a period of time when alcohol was banned in the United States.
It came about because of the protests of temperance unions, which believed that banning alcohol would reduce poverty and crime.
The American government outlawed the sale of alcohol in 1920, but this ban was not very effective.
Secret bars called speakeasies began to appear throughout the country, where people could order alcohol by speaking in code.
Prohibition also gave gangs an opportunity to profit from the illegal sale of alcohol.
People known as rum-runners would smuggle alcohol across the Canadian border in order to sell it in the U.S.
By 1933, it became clear that the ban had failed, and the government passed a new law allowing the sale of alcohol once again.