The Ku Klux Klan (KKK) is a white supremacist hate group that has a long and dark history in the United States. The KKK was founded in the aftermath of the Civil War in the Southern United States in 1865, and its primary purpose was to intimidate and terrorize African Americans, as well as other minority groups such as Jews and Catholics. The KKK used violence, including lynchings, beatings, and arson, to enforce white supremacy and maintain racial segregation.

The KKK reached its peak in the 1920s, with millions of members across the country. During this time, the KKK expanded its targets to include not only African Americans but also immigrants, Catholics, and Jews. The Klan's influence waned in the mid-20th century, but it experienced a resurgence during the civil rights movement of the 1950s and 1960s.

The KKK played a significant role in the perpetuation of racial violence and discrimination in the United States, and its legacy continues to impact race relations and social justice efforts today. Despite being associated primarily with the Southern United States, the KKK has had a presence in other parts of the country as well. Efforts to combat the KKK's racist ideology and actions have been ongoing, with organizations and individuals working to promote equality, diversity, and justice for all.