During the Gilded Age, the federal government took significant action to transform the West's social and economic landscape. Much of this had to do with the government's relationship with native peoples. Previously, most tribes were treated with some level of respect. As more white settlers moved West and more valuable resources were found in the region, Native Americans came to be viewed as obstacles. The government responded by confining Native Americans to reservations and treating any who refused as enemies of the state. This led to the subjugation of many natives peoples and opened up the region to further white settlement. In 1887, the government passed the Dawes Act which sought to end communal living arrangements among Native Americans and force them to adopt American culture.
Furthermore, although Mexicans in the western United States had been US citizens since the end of the Mexican-American War, the government deliberately refused to intervene when their land was taken from them by white settlers. This inaction allowed Mexican Americans to be pushed to the fringes of western society and to lose many economic opportunities that they had come to expect as landowners.
The government also got involved in immigration in the West. For decades, many Chinese had been coming to the region in search of economic opportunities. They were instrumental in building the railroads, cultivating land, and building cities such as Los Angeles and San Fransisco. In 1882, Congress passed the Chinese Exclusion Act which specifically barred Chinese immigrants. This law changed the racial and social makeup of the region by specifically singling out a specific ethnicity for exclusion.