In 1870, the 15th Amendment to the Constitution gave all men the right to vote. It specifically stated that a citizen had the right to vote regardless of race or color.
Some states passed laws designed to prevent black men from voting after the amendment was added. Poll taxes and literacy tests were used to keep impoverished citizens who were not taught to read from casting their vote during elections. Martin Luther King held a march in Selma that led the President to pass the Voting Rights Act of 1965, which made it easier for black men to register to vote.