In 1984, Congress passed the National Minimum Purchase Age Act, to encourage each state to institute a minimum legal purchase age (MLPA) of 21 by 1986. This act made it nearly impossible for states to receive funding from the federal government for construction of highways if the minimum legal drinking age was under 21. Since all states depend on the federal government for highway funding (which equals Billions of dollars each year) all US states enacted minimum drinking ages of 21.

Today, the minimum drinking age in all 50 US states is 21 years of age.

The main federal acts concerned with alcoholic beverages are:

Title 27 of the United States Code (Federal Law)

The Federal Alcohol Administration Act, at 27 USC §§201 - 207

The Federal Alcoholic Beverage Labeling Act, at 27 USC §§213 - 219a.