The Westward expansion helped settlers in America to move in the West. The idea for the expansion was the growing population on the Eastern side of America. The setters who settle in the West belonged to different communities with different identities. Germans, Mexicans, English, and Scottish were some of the settlers reside in the West. Large numbers of people live in the West to state a new life by indulging in farming and ranching.
I'm not entirely sure what you mean by "the West" but diversity in any given place is largely affected by immigration, which causes a blending of different cultures.