Which voting qualification was designed to prevent African Americans from voting?

There were multiple factors that prevented African Americans from voting, such as the literacy test, which was a test that would usually be very unfair. Those wishing to vote would be required to pass this test, which was very rigged. Most people would not pass due to their inability to read, while others just didn’t pass because of the racial injustice. There was also taxes, called the poll tax, voters were required to pay a small amount of money to vote, however, the African Americans were just freed from slavery so they could not afford it.