What was the impact of the westward expansion of settlers in the USA?

By the early twentieth century, the White Americans had moved westward and established control up to the west coast, displacing local tribes and carving out the entire landscape into different agricultural belts. After the war of Independence from 1775 to 1783 and the formation of the United State of America, the white Americans began to move westward. By the time Thomas Jefferson became President of the USA in 1800, over 70,000 white settlers had moved on to the Appalachian plateau through the passes. Seen from the east coast, America seemed to be a land of promise. Its wilderness could be turned into cultivated fields. Forest timber could be cut for export, animals hunted for skin, mountains mined for gold and minerals. Westward movement also forced the American Indians to give up their land and move westward.