The Enforcement Act of 1871, also known as the Ku Klux Klan Act, Third Enforcement Act, Third Ku Klux Klan Act, Civil Rights Act of 1871, or Force Act of 1871, is an Act of the United States Congress which empowered the President to suspend the writ of habeas corpus to combat the Ku Klux Klan (KKK) and other white supremacy organizations. The act was passed by the 42nd United States Congress and signed into law by United States President Ulysses S. Grant on April 20, 1871. The act was the last of three Enforcement Acts passed by the United States Congress from 1870 to 1871 during the Reconstruction Era to combat attacks upon the suffrage rights of African Americans. The statute has been subject to only minor changes since then, but has been the subject of voluminous interpretation by courts.