Prohibits the denial of the right to vote based on race, color, or previous condition of servitude. It was ratified on February 3, 1870, as the third and last of the Reconstruction Amendments.
Application: Guinn v. United States Guinn v. United States struck down the "grandfather clause" in Oklahoma's Voter Registration Act of 1910 because the clause discriminated against blacks and, therefore, violated the Fifteenth Amendment. The statute required voters to pass a reading test. However, the law exempted all those who were entitled to vote on January 1, 1866, just after the Civil War ended (and before the approval in 1870 of the Fifteenth Amendment, which guaranteed voting rights for all male citizens, regardless of race), as well as their descendants. The law allowed those whose "grandfathers" were entitled to vote in 1866 to register without passing a literacy test. (http://digital.library.okstate.edu/encyclopedia/entries/G/GU001.html)
Mobile v. Bolden Wiley L. Bolden and other residents of Mobile, Alabama brought a class action on behalf of all black citizens in Mobile. They argued that the practice of electing the City Commissioners at-large unfairly diluted the voting strength of black citizens. A district court and the U.S. Court of Appeals for the Fifth Circuit ruled in favor of Bolden. Gomillion v. Lightfoot is often referred to when talking about this case. (http://www.oyez.org/cases/1970-1979/1978/1978_77_1844)