As tens of thousands of young men shipped off to fight the Axis in WW II, they and they parents began to question the logic of declaring them old enough to fight and die for their country, but not old enough to participate in its elections. The voting age was still set at 21, and would be for several more decades, through the wars in Korea and through much of Vietnam, before Congress and President Nixon acted on it.

On this day, June 22, in 1970, in a response to widespread student protest, President Nixon signed a law lowering the voting age for all state and federal elections to 18.

Nixon expressed serious doubts about the constitutionality of his act, and sure enough it was swiftly challenged in the Supreme Court in the case of Oregon v Mitchell, with the Justices holding the federal government cannot dictate the voting age in state elections. The next year Congress overwhelmingly approved a constitutional amendment to lower the age in all government elections to 18, and three-quarters of the states easily gathered enough signatures to approve it.