The Fifteenth Amendment to the United States Constitution was ratified in 1870. It prohibits the federal and state governments from denying a citizen the right to vote based on "race, color, or previous condition of servitude." This amendment was a significant step in the fight for civil rights, particularly for African American men after the Civil War. Despite its ratification, many states found ways to circumvent the Fifteenth Amendment through discriminatory practices like literacy tests and poll taxes. It wasn't until the civil rights movement of the 1960s that more effective protections for voting rights were established, leading to the passage of the Voting Rights Act of 1965.