The Ku Klux Klan (KKK) was a white supremacist organization founded in the United States in the aftermath of the Civil War in the late 1860s. The Klan's primary targets were African Americans who had recently gained freedom from slavery, as well as their supporters and allies. The KKK used violence, intimidation, and terror tactics to maintain white supremacy and control over black communities.

The Klan's activities included lynching, burning crosses, and other violent acts aimed at instilling fear and oppression in African Americans. They also targeted white Republicans who supported civil rights and Reconstruction efforts in the South. The KKK operated clandestinely and wore white robes and hoods to conceal their identities.

Throughout the late 19th and early 20th centuries, the KKK experienced periods of decline and resurgence. The 1920s saw a significant resurgence in Klan activity, with membership expanding to millions across the country. During this time, the Klan targeted not only African Americans but also Catholics, Jews, immigrants, and other minority groups.

In the mid-20th century, the Civil Rights Movement challenged the racial segregation and discrimination that the Klan supported. The Klan responded with violence and terror, including the infamous bombing of the 16th Street Baptist Church in Birmingham, Alabama, in 1963, which killed four young African American girls.

Today, although the KKK has significantly declined in membership and influence, it still exists as a collection of fragmented and disorganized groups. The legacy of the Ku Klux Klan in Black history serves as a stark reminder of the ongoing struggle against racism and the fight for equality and justice for all.