1) Native Americans first arrived in North America around 12,000 years ago via the Bering Strait land bridge between Asia and Alaska. 2) European powers colonized different regions - Spain colonized the Southwest US and Mexico, France explored the Mississippi River region, and Britain established 13 colonies along the East Coast. 3) Through the American Revolution, Louisiana Purchase from France, Mexican Revolution, and negotiations, the borders of the US expanded to the West while Native Americans were pushed onto reservations.