As testimony of antiblack violence mounted, Congress passed the Force Act (also known as the Ku Klux Klan Act) in April 1871. A federal response to stop the terror and intimidation of southern black and white Republicans by their opponents, the act provided both civil relief for damages and criminal penalties. It was rooted in the Fourteenth Amendment’s guarantees of the rights and privileges of U.S. citizenship. The federal government dispatched troops to enforce the law and prosecuted hundreds of Klan members, often before predominantly black juries, resulting in the breakup of the Klan within a few years.
Be it enacted . . . That any person who, under color of any law, statute, ordinance, regulation, custom, or usage of any State, shall subject, or cause to be subjected, any person within the jurisdiction of the United States to the deprivation of any rights, privileges, or immunities secured by the Constitution of the United States, shall, any such law, statute, ordinance, regulation, custom, or usage of the State to the contrary notwithstanding, be liable to the party injured in any action at law, suit in equity, or other proper proceeding for redress; such proceeding to be prosecuted in the several district or circuit courts of the United States, with and subject to the same rights of appeal, review upon error, and other remedies provided in like cases in such courts, under the provisions of the [Civil Rights Act of 1866], and the other remedial laws of the United States which are in their nature applicable in such cases. . . .
SEC. 3. That in all cases where insurrection, domestic violence, unlawful combinations, or conspiracies in any State shall so obstruct or hinder the execution of the laws thereof, and of the United States, as to deprive any portion or class of the people of such State of any of the rights, privileges, or immunities, or protection, named in the Constitution and secured by this act, and the constituted authorities of such State shall either be unable to protect, or shall, from any cause, fail in or refuse protection of the people in such rights, such facts shall be deemed a denial by such State of the equal protection of the laws to which they are entitled under the Constitution of the United States; and in all such cases, or whenever any such insurrection, violence, unlawful combination, or conspiracy shall oppose or obstruct the laws of the United States or the due execution thereof, or impede or obstruct the due course of justice under the same, it shall be lawful for the President, and it shall be his duty to take such measures, by the employment of the militia or the land and naval forces of the United States, or of either, or by other means, as he may deem necessary for the suppression of such insurrection, domestic violence, or combinations. . . .
SEC. 6. That any person or persons, having knowledge that any of the wrongs conspired to be done and mentioned in the second section of this act are about to be committed, and having power to prevent or aid in preventing the same, shall neglect or refuse to do so, and such wrongful act shall be committed, such person or persons shall be liable to the person injured, or his legal representatives, for all damages caused by any such wrongful act which such first-named person or persons by reasonable diligence could have prevented.
Source: George P. Sanger, ed., Statutes at Large and Proclamations of the United States of America from March 1871 to March 1873 (Boston: Little, Brown, 1873), 13–15.