How did expansionism change the knighted states role in the world

Westward expansion impacted American society in many ways between 1800 and 1860. The westward movement began with the territory in 1803. This provided American's with the hope to “spread” democracy around the continent. Transportation evolved and adjusted because the westward enlargement exaggerated.
Westward enlargement usually had negative effects on the Native Americans. Native Americans were forced to measure on reservations. The buffalo, a vital resource, experienced fast population decline. Military conflict between Whites and Native Americans resulted in several deaths.

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