They were often ceremonially freed at potlatches , the giving of freedom to the slave being a gift from the potlatch holder .
Slaves were bought and sold in a barter economy along the same lines as any other trade goods .
Slaves were often ceremonially freed at potlatches , the giving of freedom to the slave being a gift from the potlatch holder .
Slaves were bought and sold in a barter economy along the same lines as any other trade goods .