Answer: Grandfather clauses.
Step-by-step explanation:
Grandfather clauses were statutory devices established in seven Southern states in 1895 and up to 1910. Their goal was to withhold suffrage from African Americans. These clauses instituted that only those who had the right to vote before 1866, as well as their descendants, were exempted from taxes requirements for voting.
Since former slaves were granted the franchise with the Fifteenth Amendment of 1870, grandfather clauses exclude them from the vote and were only beneficial to impoverish and illiterate white people.