A senior Democratic congressman sued former president Donald Trump Tuesday, accusing him of violating the 19th century "Ku Klux Klan Act" by supporting the January 6 attack on the US Capitol, AFP has reported. Bennie Thompson accused Trump, his lawyer Rudy Giuliani, and extremist groups the Proud Boys and Oath Keepers of violating the 1871 act by supporting efforts to stop Congress from certifying Joe Biden as the new US president. The Ku Klux Klan Act was originally created to protect the rights of African Americans after the Civil War and the end of slavery.