Native Americans are the people who occupied the land that is the United States of America today, and these individuals may also be called Indians by some. There are many different tribes of Native Americans and many people in the USA can trace their ancestry back to one of the original tribes that were present when white Europeans started to explore the world and came upon North America. When Native Americans were first exposed to the foreigners who landed here the indigenous population was almost decimated because the tribes were not immune against things as minor as the common cold. Many Native Americans were oppressed, forced to leave their traditional lands, and exposed to a variety of dangers in order to subdue them. Some Native Americans fought the settlers and then the US Government while others cooperated or even helped whites who explored the vast expanse of uncharted land.