In post-Civil War America, the Ku Klux Klan (KKK) played a role as a white supremacist organization that sought to undermine the rights and freedoms of African Americans. Founded in 1865, the Klan used intimidation, violence, and terror to enforce racial segregation and maintain white supremacy in the Reconstruction-era South. It aimed to reverse the progress made by Black citizens through laws and amendments that granted them rights. The KKK's activities contributed to systemic racism and continued social division, and it became a symbol of domestic terrorism, influencing American society and politics well into the 20th century.