Understanding ancient indigenous history changes our view of American history by showing the significant roles and influences Native Americans had before and after European contact. When Europeans first settled, relations depended on factors like how contact occurred and why settlers came, whether for trade, land or religion. Natives responded in various ways to colonialism and settlers, sometimes limiting settler ambitions through alliances or resistance. The Spanish established missions in California to convert Natives to Christianity, though this had negative impacts. Native peoples demonstrated diverse responses to the pressures of an expanding America in terms of military, political, social, cultural and religious aspects. The Indian Removal policy aimed to relocate Native tribes westward to open more land for settlers.