Denying black men the right to vote through legal maneuvering and violence was a first step in taking away their civil rights. Beginning in the 1890s. southern states enacted literacy tests, poll taxes, elaborate registration systems, and eventually whites-only Democratic Party primaries to exclude black voters.
The laws were very effective. In Mississippi, fewer than 9,000 of the 147,000 voting age African Americans were registered after 1890. In Louisiana, where more than 130,000 black voters had been registered in 1896, the number had plummeted to 1,342 by 1904.
Smithsonian National Museum of American History’s exhibit Separate is Not Equal: Brown v. Board of Education, 2004, specifically from the Segregated America section: