Scott v. Sandford was a US Supreme Court landmark decision enacted in 1857. It stated that a black person who had been imported and sold as slave, whether enslaved of free when at court, could not be considered an American citizen. Therefore his sue in front of a court made no sense because a person who is not a citizen cannot sue in court.
Dred Scott has a black citizen that tried to sue for his freedon when his owners brought him to free states, but his claim was dismissed by the US Supreme Court with the argument explained above.
