In facing the dangers of escaping, why does Douglass reason that he and his fellow slaves "did more than Patrick Henry, when he resolved upon liberty or death"?

Patrick Henry was the famous figure for saying "Give me liberty or give me death" during the Revolutionary War. Douglass finds it doubtful slaves will get liberty but more likely they would get death. I think the meaning is that he and his fellow slaves are braver than one of the founding fathers.