Which amendment prohibits poll taxes in federal elections?

The 24th Amendment to the United States Constitution specifically prohibits the imposition of poll taxes in federal elections. Ratified in 1964, this amendment was part of a broader civil rights movement aimed at ensuring voting rights and eliminating barriers that disproportionately affected minority voters and the economically disadvantaged. Poll taxes were fees charged to register to vote or to cast a ballot, which had been used as a method to disenfranchise certain groups, particularly African Americans and poor people.

By invalidating poll taxes in federal elections, the 24th Amendment sought to promote fairer access to the electoral process. Subsequent court rulings, such as the Supreme Court's decision in Harper v. Virginia Board of Elections in 1966, extended the prohibition of poll taxes to state elections as well. This amendment is a significant milestone in the ongoing struggle for voting rights in the United States.

The other options relate to different amendments, such as women's suffrage and lowering the voting age, rather than addressing the issue of poll taxes in federal elections.