The Ku Klux Klan was formed in 1866 in Pulaski, Tennessee as a secret organization that aimed to prevent Black people from voting and gaining equal rights after the Civil War. The KKK used tactics like violence and intimidation against newly freed slaves and Republicans. At its peak in the 1920s, the KKK had millions of members and targeted other groups like Jews, Catholics and immigrants in addition to Black people and Republicans. Over time federal laws were passed to curb the KKK's activities and many members were prosecuted for crimes, though offshoots still exist today espousing white supremacist ideals.