15th Amendment: The 15th Amendment to the U.S. Constitution prohibits the federal and state governments from denying a citizen the right to vote based on that citizen's 'race, color, or previous condition of servitude.'
Literacy Tests: Discriminatory voting practices that required prospective voters to pass literacy tests or meet other restrictive requirements in order to register and vote, often used to disenfranchise African American and other minority voters.
Preclearance Requirement: A provision of the Voting Rights Act that required certain state and local governments with a history of discrimination to obtain federal approval before making any changes to their voting laws or procedures.