The Gilded Age is the historical term for the period between 1870 and 1900 and it was a time of great change in America, especially for the native population.

By the mid-nineteenth century, many native tribes had already been pushed to living west of the Mississippi River but, by the 1870s, many Americans wanted to expand into this territory. As a result, a number of conflicts erupted as the natives were pushed off their lands and into reservations. War broke out in New Mexico and Arizona in 1871, for example, in which 100 natives were killed. The U.S. Army also adopted the tactic of winter campaigning, when the natives broke up into smaller bands, so that they met with less resistance. 

In 1882, Congress created the Court of Indian Offenses so that they could prosecute natives who refused to abide by American law. By the census of 1890, there were only 225,000 natives in the country and the population was quickly fading. 

Overall, then, this was a time of great change for the native population in which the federal government sought to control their movements and force them to either assimilate into mainstream society or disappear.