Which of the following was the main reason for the rapid settlement of the Great Plains (in the American West) during the late 1800s? A. Congress passed a law requiring all public lands to be sold at auction.
B. Native Americans sold most of their tribal lands directly to railroad companies.
C. Congress passed a law allowing people to claim public land and convert it to private property through homesteading.
D. Speculators bought large parcels of land and then built factory towns to attract new immigrants.