The correct answer is: "alcohol"
The Eighteenth Amendment to the US Constitution was enacted in 1919 and established the ban on "intoxicating liquours", including the prohibition of their consumption, production, sale and transportation. It is also known as the Prohibition. This amendment was the materialization of the requests of the temperance movement.
The Volstead Act or National Prohibition Act was issued in the same year for the enforcement of the prohibition provisions included in the 18th amendment.