The 15th Amendment to the U.S. Constitution states, "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 (being a slave)."
This amendment made it possible for
individual states to decide who would be able to vote
the U.S. government to decide who would be able to vote
anyone who was a citizen to be able to vote
people who were not citizens to be able to vote