The Ku Klux Klan used terrorism crime and lynching to scare African Americans out of Americans and other religious social or ethnic groups. The first clan was founded in 1866 by veterinarians of the confident. It was made to resist reconstruction by intimidating “carpetbaggers” “army scalawags” and freed slaves The KKK quickly adopted violent methods, causing a backlash by many Southern elites who saw the Klan as an excuse for federal troops to continue their activities. The organization declined from 1868 to 1870 and was destroyed by President Ulysses S. Grant.

In 1915, the second Klan was founded using the same name. The film The Birth of a Nation and the sensationalized newspaper coverage of the trial, conviction and lynching of Leo Frank of Georgia sparked the Klan's revival. It grew amid social fears aroused by rapid changes in many major cities absorbing immigrants from southern and Eastern Europe; and the Great Migration of Southern blacks and whites from rural areas. The second KKK was a formal fraternal organization, with a national and state structure, that paid thousands of men to organize local chapters all over the country.

At the end of the American Civil War radical members of Congress attempted to destroy the white power structure of the Rebel states. The Freeman's Bureau was established by Congress on 3rd March, 1865. The bureau was designed to protect the interests of former slaves. This included helping them to find new employment and to improve educational and health facilities. In the year that followed the bureau spent $17,000,000 establishing 4,000 schools, 100 hospitals and providing homes and food for former slaves.

More than 40 different Klan groups exist, many having multiple chapters, or “klaverns,” including a few that boast a presence in a large number of states. There are over a hundred different Klan chapters around the country, with a combined strength of members and associates that may total around 5,000.