Poll taxes, literacy tests, and grandfather clauses were used in the South after 1890 to (1) support the goals of the Freedmen’s Bureau (2) deny suffrage rights to African Americans (3) undermine the “separate but equal” ruling of the Supreme Court (4) to enforce the amendments enacted during the Civil War and Reconstruction

(2) deny suffrage rights to African Americans.

After the Civil War and Reconstruction period, particularly starting in 1890, southern states began to enact various laws and practices such as poll taxes, literacy tests, and grandfather clauses with the deliberate intention of disenfranchising African American voters. These discriminatory measures were means of circumventing the 14th and 15th Amendments to the Constitution, which granted African Americans citizenship and the right to vote, respectively.

Poll taxes were fees individuals had to pay to vote. Since many African Americans and poor whites did not have disposable income, this effectively excluded them from voting. - Literacy tests consisted of difficult questions about government and the Constitution. These tests were often administered in a biased manner, allowing unfair discretion to the test givers to pass or fail individuals on a subjective basis. Grandfather clauses allowed individuals to circumvent literacy tests and poll taxes if their grandfathers had been eligible to vote before the Civil War. This provision obviously excluded African Americans, whose ancestors were enslaved and denied the franchise before that time.

The use of poll taxes, literacy tests and grandfather clauses in the southern United States were part of a broader system of racial segregation and oppression known as "Jim Crow" laws. These laws institutionalized the disenfranchisement and marginalization of African Americans despite their constitutional rights. It was not until the Civil Rights Movement of the 1950s and 1960s, culminating in legislation such as the Civil Rights Act of 1964 and the Voting Rights Act of 1965, that these practices were effectively challenged and dismantled. The "Separate but Equal" doctrine, which was established by the Supreme Court case Plessy v. Ferguson in 1896, was another facet of the Jim Crow era that mandated segregation of public facilities, claiming that they could be separate as long as they were equal. This was in direct contradiction to the goals of the Civil War and Reconstruction Amendments, which aimed to ensure equality and protect the rights of former slaves and their descendants. The "Separate but Equal" doctrine was not undermined by the efforts to disenfranchise African Americans, but rather was part of the same overall regime of segregation and racial discrimination until it was overturned by Brown v. Board of Education in 1954.