If my knowledge of history is correct, slaves in the US had to right to sue, unless they were sueing to claim that they were not actually slaves; since, until t

If my knowledge of history is correct, slaves in the US had to right to sue, unless they were sueing to claim that they were not actually slaves; since, until the court decided the suit, it was possible that they were not actually slaves, and so they had to be given the right to be heard in court.