One of the results of the concept of Manifest Destiny was that it became a United States foreign policy during the 19th century. The popular belief that God was behind the fulfillment of American expansionism helped to justify the war with Mexico that began after Texas declared independence. The territory the U.S. gained from its victory in the war with Mexico then provided a path for western migration to the Pacific coast and a solution to the issue of heavy population growth and immigration that was taking place in the eastern half of the country.
A belief in Manifest Destiny also served to justify the westward settlers taking over lands formerly occupied by Native Americans. The indigenous tribes were viewed by many as uncivilized savages and racial and religious rhetoric was often incorporated into Manifest Destiny's vision of civilizing Native Americans so that they could live peacefully with the white settlers. The end result, however, was conflict, and in some cases, forced relocation of entire indigenous tribes.