Ku Klux Klan Act passed by Congress

With passage of the Third Enforcement Act, popularly known as the Ku Klux Act, Congress authorizes President Ulysses S. Grant to declare martial law, impose heavy penalties and use military force to suppress terrorist organizations—particularly the Ku Klux Klan (KKK).

Passed as the third in a series of increasingly stringent laws, the act came in response to a an increasingly brutal campaign of violence and intimidation by the KKK and others to repress Black Americans' expanding political and civil rights. The law made it a federal crime to deny any group or individual “any of the rights, privileges or immunities, or protection, named in the Constitution.” And it gave the president enforcement powers, including deployment of the military, suspension of habeus corpus or “other means, as he may deem necessary.”

Founded in 1865 by a group of Confederate veterans, the KKK rapidly grew from a secret social fraternity to a paramilitary force bent on reversing the federal government’s progressive Reconstruction era-policies in the South—especially those that elevated the rights of Black Americans. Under a platform of philosophized white racial superiority, the group employed violence as a means of pushing back Reconstruction gains under the 13th, 14th and 15th Amendments to the Constitution, which granted Black Americans emancipation, citizenship, voting rights, due process and more.

After large numbers of Black Americans voted in South Carolina's state election in 1870, the KKK's brutal campaign of violence escalated. Most prominent in counties where the races were relatively balanced, the KKK engaged in terrorist raids at night against Black Americans and white Republicans, employing intimidation, destruction of property, assault, rape and murder to achieve its aims and influence upcoming elections. In a few Southern states, Republicans organized militia units to break up the Klan.

In 1871, passage of the Ku Klux Act led to President Grant placing nine South Carolina counties under martial law. Troops made copious arrests, and high-profile trials led to hundreds of convictions or guilty pleas. But after the political pendulum swung in the South after Reconstruction, systemic repression of Black American rights deepened. Over time, the U.S. Supreme Court weakened the Ku Klux Act, narrowing its interpretation and shifting enforcement and prosecution from the federal to the state level.