What minority group has been discriminated against the most to prevent them from voting?

Historically, African Americans in the United States have faced significant discrimination aimed at preventing them from voting. Following the Civil War and the passage of the 15th Amendment, various tactics such as literacy tests, poll taxes, and outright intimidation were used, particularly in the Jim Crow South, to disenfranchise Black voters. This systemic discrimination persisted for decades until the Voting Rights Act of 1965 aimed to eliminate such barriers. Despite legal advancements, challenges to voting rights continue to affect minority groups today.