While many KKK members were Democrats, the Klan was not started by the Democratic Party.
For several years the claim that the Democrats formed the Ku Klux Klan (KKK) has been making rounds on social media. The Ku Klux Klan was founded in 1866 by ex-Confederate soldiers Frank McCord, Richard Reed, John Lester, John Kennedy, J. Calvin Jones, and James Crowe in Pulaski, Tennessee. The group was originally a social fraternity but quickly became a violent white supremacist group.
Experts agree that there exists a historic link between the Democrats and the KKK, as many angry Southern whites during the 1860s and 1870s were Democrats, and some joined the KKK. Former Confederate General Nathan Bedford Forrest was the KKK's first grand wizard, and he also spoke at the 1868 Democratic National Convention. But according to J. Michael Martinez, who wrote the 2007 book 'Carpetbaggers, Cavalry and the KKK,' it's misleading to say the Democratic Party founded the Klan. Therefore, while some Democrats supported the KKK, there's no evidence the Democratic Party founded the group.