Joseph Buford Cox is a person who did some bad things. He was a member of a group called the Ku Klux Klan, which did not like people who had different skin colors than them. This group did bad things like hurting and killing people who looked different than them.
Joseph Buford Cox did some bad things because he believed that white people (people with light skin) were better than other people. He hurt and killed people because of their skin color and did not think that everyone should be treated equally.
This is not a nice thing to do and hurts a lot of people. It is important to remember that everyone should be treated kindly and fairly, no matter what they look like.