How did the civil war affect the settlements along the buffalo plains

As Far Western Expansion picked up, it became clear that just as before, the goals of American expansionists conflicted with the needs of the Indians in the area of expansion. Many of the Plains tribes depended on the buffalo for survival. Several tribes followed the buffalo migration, harvesting conservatively to fill tribal needs. The Indians ate buffalo meat, used its hide for clothing and shelter. Sinews were used as bowstrings and bones were used as tools and weapons. Buffalo fat was used as grease, hoofs used to make glue, and even buffalo dung was used for fuel. By the 1870s, however, the buffalo population was on the decline. Non-Indians killed the buffalo for their pelts, to feed railroad construction crews, or even just for the pure sport of it. Army commanders who operated in the West often attempted to drive the Indians off of desired lands by killing the buffalo as a way to deprive the Indians of supplies. Between 1872 and 1875, only three years, hunters killed 9 million buffalo, most often taking the skin and leaving the carcass to rot in waste. By the 1880s the Indian way of life was ruined and the way was cleared for American settlement of the Plains.

im not sure its either a leader of a group of congresspeople or a person from a congressmans district

sorry im not sure