In the early and mid-19th century, industry in the united states expanded greatly in part to

Westward Expansion generally had negative effects on the Native Americans. Native Americans were forced to live on reservations. The buffalo, an important resource, experienced rapid population decline. Military conflict between Whites and Native Americans resulted in many deaths.

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It's D.increased immigration in industrial areas.

Explanation: In USAtestprep

it was the "4. potsdam" conference that demanded the unconditional surrender of japan, since it was clear that the japanese would continue to find until the very last man otherwise.