which constitutional amendment guaranteed that african-americans had the right to vote?
African Americans gained the right to vote through the 13th, 14th, and 15th amendments. Which abolished slavery, granted full citizenship to African Americans, and guaranteed the right to vote to men regardless of their race, color, or previous condition of servitude. Eighteen year olds were granted the 26th amendment, since many of them had fought in the Vietnam war.
Passed by Congress February 26, 1869, and ratified February 3, 1870, the 15th amendment granted African American men the right to vote.