Which amendment abolished the poll tax?

The 24th Amendment to the United States Constitution abolished the poll tax in federal elections. Ratified in 1964, this amendment was a significant step towards eliminating economic barriers that prevented citizens, particularly African Americans and poor individuals, from exercising their right to vote. The poll tax had been used in some states as a prerequisite for voting, effectively disenfranchising those who could not afford to pay it. By prohibiting this requirement, the 24th Amendment aimed to ensure that voting rights were not contingent upon one's socio-economic status.

In terms of context, the 26th Amendment, which lowered the voting age to 18, and the 21st Amendment, which repealed Prohibition, do not address the issue of poll taxes. The Sherman Anti-Trust Act pertains to regulating unfair business practices and does not relate to voting rights or amendments concerning electoral processes. Thus, the focus of the 24th Amendment on voting rights makes it the correct choice for this question.