Challenging the system passively.
Try to escape. That is all they could do. They would wait until the right moment and then slip away without anyone noticing. They would only take what they could fit on their backs. sometimes they woudl not even do that. Tehy would jsut go with the clothes on their backs. Sometimes the slave owners did not even notice that they were gone. They would even sometimes slip out when their master was not looking during the time that they worked in the fields.