I teach about the Colfax Massacre in my AP US History courses. One of the things that was utilized to "control" the black population and make it easier to target was that many areas of the south made it illegal for blacks to own guns--which the US Supreme Court assented to at the time. The courts, until into the 20th Century, generally put for the Bill of Rights in the US Constitution was only considering the actions of the federal government, and state governments could abridge them if the so chose.