On this day in 1870, the 15th Amendment to the US Constitution was ratified.  Its text is brief.

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.

The Congress shall have the power to enforce this article by appropriate legislation.

The passage of the Amendment was a staggeringly large step toward race equality in America.  Yet even before three-quarters of the states ratified it, racists began to deter blacks from exercising their new political power: the power of the ballot.  The campaign against them, consisting of intimidation, violence, and legal obstacles, was particularly brazen in the former slave states.  Shockingly, it would be another 100 years before the promise of the 15th Amendment became something like a reality.  With the new assault on voting rights we see today, the fragility of this Constitutional guarantee is obvious.

Image: from this source.