The National Minimum Drinking Age Act of 1984 was passed on July 17, 1984 by the United States Congress

United States Congress

The United States Congress is the bicameral legislature of the federal government of the United States, consisting of the Senate and the House of Representatives. The Congress meets in the United States Capitol in Washington, D.C....

 as a mechanism whereby all states would become thereafter required to legislate the age of 21 years as a minimum age for purchasing and publicly possessing alcoholic beverage

Alcoholic beverage

An alcoholic beverage is a drink containing ethanol, commonly known as alcohol. Alcoholic beverages are divided into three general classes: beers, wines, and spirits. They are legally consumed in most countries, and over 100 countries have laws regulating their production, sale, and consumption...

s. Under the Federal Aid Highway Act, a state with a minimum age below 21 would be subjected to a ten percent decrease in its annual federal highway apportionment.

While this act did not outlaw the consumption of alcoholic beverages by those under 21 years of age, seven states and Washington D.C.