# Ku Klux Klan Act **Status: stub — expand.** Signed by President **Ulysses S. Grant on April 20, 1871**, the third of the Reconstruction-era Enforcement Acts. It made Klan terror a federal crime, authorized federal prosecution where states would not act, and **empowered the President to suspend the writ of habeas corpus** in areas of "rebellion" against federal authority. Grant used that power once: on **October 17, 1871** he declared **nine South Carolina counties** in rebellion and suspended the writ. Federal troops under Maj. Lewis Merrill made mass arrests — more than 600 men detained by the end of the year — producing the South Carolina Klan trials of 1871–72 and, briefly, the effective destruction of the Klan in that state. **Why it matters twice over.** It is the only peacetime suspension of habeas corpus used against domestic political violence *by* the state's own sympathizers, and its surviving civil provision is **42 U.S.C. § 1983**, the statute under which most modern constitutional-rights suits against state officials are brought — including many filed against the second Trump administration. ## See Also - [[Habeas Corpus Timeline]] · [[Habeas Corpus]] · [[Suspension Clause]]