The Ku Klux Klan (), commonly shortened to KKK or Klan, is an American Protestant-led Christian extremist, white supremacist, far-right hate group. It was founded in 1865 during Reconstruction in the devastated South. Various historians have characterized the Klan as America's first terrorist group. The group contains several organizations structured as a secret society, which have frequently resorted to terrorism, violence and acts of intimidation to impose their criteria and oppress their victims, most notably African Americans, Jews, and Catholics. A leader of one of these organizations is called a grand wizard, and there have been three distinct iterations with various other targets relative to time and place.
The first Klan was established in the Reconstruction era for men opposed to Radical Reconstruction and founded by Confederate veterans that assaulted and murdered politically active Black people and their white political allies in the South. Federal law enforcement began taking action against it around 1871. The Klan sought to overthrow Republican state governments in the South, especially by using voter intimidation and targeted violence against African-American leaders. The Klan was organized into numerous independent chapters across the Southern United States. Each chapter was autonomous and highly secretive about membership and plans. Members made their own, often colorful, costumes: robes, masks and pointed hats, designed to be terrifying and to hide their identities.
The second iteration of the Klan originated in the late 1910s, and was the first to use cross burnings and standardized white-hooded robes. The KKK of the 1920s had a nationwide membership in the millions and reflected a cross-section of the native born white Protestant population. The third and current Klan formed in the mid 20th century, was largely a reaction to the growing civil rights movement. It used murder and bombings to achieve its aims. All three iterations have called for the "purification" of American society. In each era, membership was secret and estimates of the total were highly exaggerated by both allies and enemies.
Each iteration of the Klan is defined by non-overlapping time periods, comprising local chapters with little or no central direction. Each has advocated reactionary positions such as white nationalism, anti-immigration and—especially in later iterations—Nordicism, antisemitism, anti-Catholicism, right-wing populism, anti-communism, homophobia, anti-atheism, and Islamophobia.
