What might be one important consequence of a law that required any slave caught running toward Canada and freedom be returned to his or her master?

The consequence of such law would be that, there will be choas with the tendency of war occuring as a result of such. This is because, there are those that are not in support of slavery while there are others that are in support of it. We the capture of a slave close to Canada will cause issues among the people leading to breakdown of law and order.

Explanation:

disease was the number one killer of native peoples. they had had little exposure to the diseases of europe. this led to some villages being almost completely wiped out and some tribes destroyed.