Which amendment states that citizens eighteen and older can vote?

The twenty-sixth amendment to the United States Constitution explicitly establishes the voting age at eighteen years. Ratified in 1971, this amendment was a response to the increasing arguments that individuals who were old enough to be drafted for military service in the Vietnam War should also have the right to vote. As a result, it guarantees that citizens who are eighteen years of age or older cannot be denied the right to vote based on age, providing a significant expansion of voting rights in the U.S.

The other amendments listed do not pertain to the voting age. The twenty-fourth amendment addresses the prohibition of poll taxes in federal elections. The twelfth amendment relates to the procedure for electing the President and Vice President, while the nineteenth amendment grants women the right to vote, but does not specify an age requirement. This context reinforces the importance of the twenty-sixth amendment, which directly correlates to the voting age of citizens.