What did the National Minimum Drinking Age Act of 1984 do?

Question

Quizplus · Accepted Answer

While some states already had the minimum drinking age set at 21, the National Minimum Drinking Age Act of 1984 made the legal drinking age the same in every state (which meant many had to raise it).
Since 1984, the drinking age has been the same in all 50 states. In some states, people under 21 who had already been drinking legally were grandfathered into the new law, but in others they were not.

What Did the National Minimum Drinking Age Act of 1984