Prohibition: The Ignoble Experiment The 18th Amendment , considered to be one of the biggest follies of the nation, was brought about with the intent to sincerely help the U.S., but more harm came from it than good. Prohibition, also known as the 18th Amendment , was ratified on January 29th, 1920 and was repealed on December 5th, 1933 with the ratification of the 21st Amendment which nullified prohibition. The 18th Amendment stated that it was illegal to manufacture, transport, and sell alcoholic beverages in the United States. "The national prohibition of alcohol was undertaken to reduce crime and corrupti