The 15th Amendment, that which gave all men the right to vote regardless of race, was ratified today in 1870. The victory was shortlived however, as just as fast as African Americans we voted into office they were swept out again and the Jim Crow era began.
African American males were kept from voting in many states using a bevy of nefarious means, from bogus literacy tests to outright murder.
It was be almost 100 years and the passing of the Civil Rights Act and Voting Rights Act (1964 and 1965 respectively) that would finally empower that right laid to paper so long ago.