What caused Chief Joseph to flee to Canada, and why
were he and his people captured?

The mayor of that time opened up the Wallowa Valley to white settlement, and decided that the roaming Nez Perce band move onto reservations immediately. When 3-4 braves when out to avenge a father's death, Chief Joseph allowed it. As he prepared for war he met in discussion with Oliver O. Howard, but still the message he received was the same, move to the reservation lands. As Chief Joseph was rushed across the river with little notice, he had to leave many horses and cattle behind, and many died in the crossing of the river for it had swelled past the banks and was a bad crossing season. At the other edge of the river they stopped to rest before moving on, when confronted by troops, they fought, and then withdrew and began their flee to Canada. His people were captured for standing up against the white settlers, and for refusing to follow the unfair laws, it was also to be an example for the other Native American tribes they were moving to reservation lands.

Explanation:

answer; (b) capitalism;