The Voting Rights Act of 1965 guaranteed the free exercise of the franchise to minorities, particularly African Americans. It banned various means that had previously been used to restrict de jure equal suffrage, such as literacy tests.
Signing of the Voting Rights Act, President's Room, U.S. Capitol, Washington, DC, black-and-white photograph, 6 August 1965, photographer: Yoichi Okamoto; source: The Lyndon Baines Johnson Presidential Library, A1030-17a, public domain.