Which amendment to the Constitution granted African American men the right to vote?

The 15th Amendment to the United States Constitution specifically granted African American men the right to vote. Ratified in 1870, this amendment states that the right to vote cannot be denied or abridged by the United States or any state based on race, color, or previous condition of servitude. This was a significant development in the post-Civil War era, aiming to address and rectify the injustices faced by African Americans, particularly in the Southern states.

The other amendments mentioned have different focuses: the 19th Amendment, ratified in 1920, granted women the right to vote; the 24th Amendment, ratified in 1964, prohibited poll taxes in federal elections; and the 26th Amendment, ratified in 1971, lowered the voting age to 18. While these amendments expanded voting rights, they did so for different groups or circumstances and do not specifically pertain to African American men. Thus, the 15th Amendment is the correct answer regarding the right to vote for African American men.