The 24th Amendment to the US Constitution was passed by Congress on January 23, 1964 to make poll taxes illegal for federal elections. Poll taxes are taxes that some states began charging during Reconstruction as a way to African Americans from voting. In 1966, the Supreme Court extended the protection against poll taxes to include state elections, citing the equal protection clause of the 14th amendment.
Section 1.
The right of citizens of the United States to vote in any primary or other election for President or Vice President, for electors for President or Vice President, or for Senator or Representative in Congress, shall not be denied or abridged by the United States or any state by reason of failure to pay any poll tax or other tax.