After the Civil War, Congress enacted several pieces of civil rights legislation including: the Civil Rights Act of 1866 and 1871, the Enforcement Act of 1870, the Force Act of 1871, the Ku Klux Klan Act, and the Civil Rights Act of 1875. These acts made federal courts the principal agency for the enforcement of basic constitutional and civil rights. As a result these lower federal courts emerged with significantly greater importance supplanting state courts as the principal forum for enforcing federal law.
Several of the provisions of these Post Civil War Federal Civil Rights Acts still exist today as codified statutes. However, the most important still-existing provision is 42 U.S.C. § 1983. It was originally enacted a few years after the American Civil War. One of the chief reasons for its passage was to protect southern blacks from the Ku Klux Klan by providing a civil remedy for abuses then being committed in the South. The statute has been subject to only minor changes since then, but has been the subject of voluminous interpretation by courts.
In its early history, the act had very little effect. Then the 1961 US Supreme Court case of Monroe v. Pape, 365 U.S. 167 (1961), resurrected the effect of 42 U.S.C. § 1983. This statute quickly became the fulcrum of constitutional tort litigation. In the Monroe case, the police officer defendants argued that the “under color of state law” provision of § 1983 limited liability to cases in which positive state law authorized acts that violated the Constitution. Under the pre-1961 view, officers who acted in an unconstitutional manner, and in violation of state law, would not be liable under § 1983. The Monroe Court rejected this interpretation and found an independent basis for remedies for acts, authorized or not by state law, that were violative of the Constitution or federal law.