Final answer:
The Voting Rights Act of 1965 eliminated the 'grandfather clause,' a discriminatory practice used to disenfranchise African American voters by exempting White voters from literacy tests and poll taxes if their ancestors had voted before the Fifteenth Amendment.
Step-by-step explanation:
The Voting Rights Act of 1965 eliminated the so-called grandfather clause, which had previously disqualified many African American voters. The grandfather clause was a provision in some southern states that allowed illiterate White people to vote because their ancestors had been able to vote before the Fifteenth Amendment was ratified. This device, along with others such as poll taxes and literacy tests, was employed in the post-Reconstruction era to disenfranchise Black voters, ensuring that African Americans would not be exempt from such tests while White voters could bypass them if their predecessors had the right to vote prior to Black suffrage.
Grandfather clauses, literacy tests, and poll taxes were utilized to maintain the racial hierarchy established under Jim Crow laws. It wasn't until the Voting Rights Act of 1965 that literacy tests were prohibited, and federal examiners were sent to seven Southern states to ensure the registration of black voters, dismantling key obstacles to voting and making significant strides in civil rights progress.