When did the us first have a legal drinking age?

The minimum purchase and drinking

age is a state law. Each individual U.S. state establishes by law

the minimum age at which an individual may purchase alcoholic

beverages. The U.S. Government passed the National Minimum Drinking

Age Act on July 17, 1984. This did not change the drinking age.

However, it forced the individual states to establish the minimum

drinking age as 21 or lose 10% of their federal highway funding.

The minimum drinking age is 21 in all 50 U.S. states.