The densest region of american population west of the appalachian mountains was adjacent to which river?

When conducting research for forming a hypothesis, which practice should historians follow?

During industrialization which led to an explosion of new economic theories

Why did the dakota sioux start an uprising in 1862? a.the government had not followed through with promises of . b.the government had given to an enemy american indian group. c.the sioux were not allowed to sell hunted animals to the us government. d.the sioux had made an agreement with neighboring tribes to attack.