The fifteeth Amendment to the Constitution?

Answer 1

The 15th Amendment to the U.S. Constitution is the last in sequence of the "Civil War Amendments."

It guarantees black men the right to vote:

Section 1.

The right of citizens of the United States to vote shall not be denied or abridged by the United States or by any state on account of race, color, or previous condition of servitude.

Section 2.

The Congress shall have power to enforce this article by appropriate legislation.

It was ratified in 1870, but the country was slow to enfranchise black men. The use of discriminatory poll taxes, literacy tests, etc., did not end completely until the Voting Rights Act of 1965 was passed by Congress.

Answer 2

The right of citizens of the United States to vote shall not be denied or abridged by the United States or by any State on account of race, color, or previous condition of servitude.