Final answer:
The best explanation for the role of immigrants in the western expansion of the United States is that they often had farming experience and settled in the Great Plains area to make use of the available cheap land and to fulfill their vision of achieving economic prosperity.
Step-by-step explanation:
The role of immigrants in the United States during the western expansion from the late 1800s to early 1900s was integral to the development of the American West. The correct answer to the question about the role of immigrants in the United States during this period is 'C) They often had farming experience, so they settled in the Great Plains area.'
This is because many immigrants, particularly from Northern Europe, were drawn to the opportunities in the West for various reasons, including the availability of cheap land through acts like the Homestead Act, and the potential for agricultural development in the Great Plains. Furthermore, the Manifest Destiny ideology of the era supported the idea of Americans (including new immigrants) expanding westward, not only for economic opportunity but also to spread American values.
Immigrants played a significant role in settling and developing the West. Many of them had experience in farming and were looking for a chance to own land and improve their economic situation. European immigrants such as Germans, Scandinavians, and Irish formed strong communities and contributed to the diverse cultural landscape of the West. The Homestead Act of 1862 further incentivized westward migration by offering land to settlers who were willing to move and develop it.