The 15th Amendment to the United States Constitution, ratified in 1870, 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 milestone in the fight for civil rights, particularly for African American men, following the Civil War and the abolition of slavery. Despite its ratification, the 15th Amendment faced numerous challenges, as many states implemented discriminatory practices like literacy tests and poll taxes to suppress the voting rights of African Americans. It wasn't until the civil rights movement of the 1960s that these injustices were more effectively addressed, leading to further legislation to protect voting rights.