There were many famous people who were members of the Notorious Ku Klux Klan throughout history. None of the famous people who were definitely proven to be KKK members were U.S. presidents, but there were some alleged members. This means that they were believed to be members. Some of the proven members were Hugo Black, Rice W. Means, and Edward L. Jackson. The two presidents who were believed to be KKK members include Warren G. Harding.
There are accounts through several people who believe he was a member. The opposing candidates of Harry S. Truman stated that he was a member of the Ku Klux Klan at some point. Two friends of his convinced Truman to join the Klan, but it is not for certain whether this is true or not.