Poll taxes were introduced because the white voters knew that the African-American community could not pay these taxes due to poverty. Another mechanic common was a literacy test where the African-American community almost always failed because they were segregated when it came to education.
During the Jim Crow era, a tax on the poll was enforced which discouraged the African Americans and poor white of southern states to tax. The economic condition of the African American was already suffering and a tax on the poll was n extra burden. The rich whites want to control the voting by using these taxes. It was finally abolished by the 24th amendment of the United States Constitution.
