Answer:
The loss of the bison and the growth of white settlement drastically affected the Native Americans' lives in the West. Despite occasional victories in the conflicts that resulted, the American Indians seemed doomed to defeat by more significant water numbers of settlers and the military force of the U.S. government. Gold rush and mining opportunities (silver in Nevada) The opportunity to work in the cattle industry; to be a “cowboy” Faster travel to the West by railroad; availability of supplies due to the railroad. The opportunity to own land cheaply under the Homestead Act. Native peoples of America had no immunity to the diseases that European explorers and colonists brought with them. Diseases such as smallpox, influenza, measles, and even chicken pox proved deadly to American Indians. Europeans were used to these diseases, but Indian people had no resistance to them.