The Civil War ended the institution of slavery. Despite the Constitutional protections of the Fourteenth and Fifteenth Amendments, peace ushered in a new struggle that would affect American society and culture for over 100 years. In the South, the war to defend slavery was transformed into a conflict to repress free blacks through custom, law, intimidation, and violence. In one sense the Civil War continued but in a different form.

The Ku Klux Klan (KKK) emerged in 1866 from the Pulaski, Tennessee, law office of Judge Thomas M. Jones as a social movement responding to the Thirteenth Amendment's legislated end of slavery after the defeat of the Confederacy. Six former Rebel soldiers changed the Greek word "kuklos" ("circle or band") to "Ku Klux," adding the redundant "Klan." Based on fraternity rituals, the Klansmen disguised themselves as spirits to torment the free black population.

Under Reconstruction, the...