Ratified in 1870, the 15th Amendment to the U.S. Constitution declared, “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.” While this amendment, passed in the wake of the Civil War, granted suffrage to African American men, it would take another 95 years -- and the Voting Rights Act of 1965 -- for its promise to become a reality.

Background of the Amendment

After the Civil War, the Radical Republicans -- those with strong anti-slavery sentiments -- began pushing laws and amendments designed to expand civil rights for African Americans. In 1867, Congress passed a law mandating that former Confederate states permit black male suffrage in their constitutions as a prerequisite for readmission to the Union -- even though many Northern states still prohibited blacks from voting. But because these Republicans' grip on Congress was waning and Northern Democrats were resurgent, the Radical Republicans saw the need for universal black male suffrage, even in Northern states. And they knew they needed to act fast, before they lost power.

Grant's Election

The Republicans nominated Ulysses S. Grant in 1868. While their platform continued to demand that Southern states permit African Americans to vote, it did not do so for Northern states, where the idea of black suffrage was widely unpopular. Grant won -- but by a very small amount. So small, in fact, that Republicans came to believe that they needed Northern black votes to maintain their majority. Early in 1869, these Republicans proposed a constitutional amendment to grant blacks the franchise.

Passing the Amendment

Congress debated the proposed amendment for two months, eventually settling on language that didn’t mention African Americans at all, but instead used to terms “race,” “color,” and “previous condition of servitude.” After Congress passed the law, it went to the states -- and ironically, because of the Republican governments that controlled the former Confederate states, passage there was easy. More difficult was attaining the needed approval of 17 of the remaining 26 Northern and Western states -- only nine of which then allowed blacks to vote. Nonetheless, and despite Democrats’ claims that the amendment trampled on states' rights, the Republicans were victorious. On February 2, 1870, Georgia pushed the amendment over the edge. According to the Constitution, blacks could no longer be disqualified from voting on account of their race.

The Voting Rights Act

While the Constitution guaranteed blacks the right to vote, that's not how it worked out in practice. Soon after the amendment, Southern white supremacists, including members of the Ku Klux Klan, began to intimidate and even murder blacks who tried to vote. After the disputed 1876 presidential election, Republicans agreed to withdraw federal enforcement of civil rights laws from the South in exchange for Southerners supporting their candidate, Rutherford B. Hayes. When federal officials left, Southern politicians passed myriad laws designed to prevent blacks from voting, including literacy tests and voting taxes. By 1940, only 3 percent of eligible African Americans in the South were registered to vote.

In 1962, Congress passed the 24th Amendment, which banned voting taxes. This amendment was ratified in 1964. The next year, 1965, President Lyndon B. Johnson pushed through the Voting Rights Act, a law that prohibited states from erecting barriers to political participation on the basis of race.