The Grandfather Clauses, poll taxes, and the literacy tests that were used in the Southern states after 1890 were used to deny the suffrage rights to the African Americans. The grandfather clause only allowed people to vote who had voted previously. Since the African Americans had never voted, this made it impossible for them to vote. Since the African American people were slaves previously and had no formal schools, they couldn't pass the literacy tests. Also, they couldn't afford to pay the poll taxes. This all changed with the Civil Rights Act in 1964.