"KKK" redirects here. The Ku Klux Klan (pronounced /ˈ k uː ˈ k l ʌ k s ˈ k l æ n, ˈ k j uː/),[a] commonly called the KKK or simply the Klan, is the name of three distinct movements in the United States that have advocated extremist reactionary positions such as white supremacy, white nationalism, anti-immigration and—especially in later iterations—Nordicism,  anti-Catholicism   and antisemitism. Historically, the KKK used terrorism—both physical assault and murder—against groups or individuals whom they opposed. All three movements have called for the "purification" of American society and all are considered right-wing extremist organizations.   
The first Klan flourished in the Southern United States in the late 1860s, then died out by the early 1870s. It sought to overthrow the Republican state governments in the South during the Reconstruction Era, especially by using violence against African American leaders. With numerous chapters across the South, it was suppressed around 1871, through federal law enforcement. Members made their own, often colorful, costumes: robes, masks and conical hats, designed to be terrifying and to hide their identities. 
The second group was founded in 1915 and it flourished nationwide in the early and mid-1920s, particularly in urban areas of the Midwest and West. Rooted in local Protestant communities, it opposed Catholics and Jews, while also stressing its opposition to the Catholic Church at a time of high immigration from mostly Catholic nations of southern and eastern Europe. This second organization adopted a standard white costume and used code words which were similar to those used by the first Klan, while adding cross burnings and mass parades to intimidate others.
The third and current manifestation of the KKK emerged after WWII, in the form of localized and isolated groups that use the KKK name. They have focused on opposition to the Civil Rights Movement, often using violence