Congress followed the Civil Rights Act of 1870 with an 1871 law “to enforce the Provisions of the Fourteenth Amendment to the Constitution of the United States,” which came to be known as the Third Enforcement Act or the Second Ku Klux Klan Act. Like the prior year’s legislation, the act was designed in large part to protect African Americans from Klan violence during Reconstruction, giving those deprived of a constitutional right by someone acting under color of law the right to seek relief in a federal district or circuit court. This part of the legislation was later made a part of the United States Code as 42 U.S.C. §1983 and served as the basis for many federal court lawsuits against state and local officials.
See also:
Spotlight on Judicial History: The South Carolina Ku Klux Klan Trials of 1871-1872