Complex sentence: He strongly opposed the Dawes Act, intended to break up communal Native American lands and force assimilation of the people, accurately stating that it was directed at forcing the Indians to give up their land so that it could be sold to white settlers.
Split into simpler sentences: He strongly opposed the Dawes Act, intended to break up communal Native American lands and force assimilation of the people. He accurately said that it was directed at forcing the Indians to give up their land so that it could be sold to white settlers.