The U.S. government forced the Native Americans (then called Indians) to move to reservations in exchange for protection from attacks by white settlers. In addition, the Indians were supposed to be given a yearly payment that would include money in addition to food, livestock, household goods and farming tools. (Unfortunately there is evidence that many of the treaties were not adhered to. Once the Indians were relocated, they were often forgotten about).
The Indians were removed to distant reservations, often on land that was nowhere nearly as good as where they had been living.
