Which amendment abolished poll taxes in federal elections?

The 24th Amendment is the correct choice because it specifically prohibits the imposition of poll taxes in federal elections. Ratified in 1964, this amendment was a significant step in the civil rights movement, aimed at eliminating financial barriers that prevented low-income citizens, particularly African Americans and poor whites, from voting. Poll taxes had been used primarily in Southern states as a means to disenfranchise these voters, and the 24th Amendment was designed to ensure that no citizen would be required to pay a tax in order to exercise their right to vote in federal elections.

The other amendments listed do not address the issue of voting rights in relation to poll taxes. The 22nd Amendment deals with presidential term limits, the 26th Amendment establishes the voting age at 18, and the 20th Amendment focuses on the terms of office for Congress and the President, none of which pertain to poll taxes. Thus, the 24th Amendment is distinctly recognized for abolishing poll taxes in federal elections, making it the correct answer.