Final answer:
Most of the people who migrated to the Great Plains in the late 1800s became farmers and ranchers.
Step-by-step explanation:
During the late 1800s, most of the people who migrated to the Great Plains became farmers and ranchers. The expansion of the railroad and the availability of better farm equipment allowed for large farms to succeed through economies of scale. Although there were other opportunities such as mining and cattle, the majority of settlers in the Great Plains focused on agriculture.
Learn more about migration to the Great Plains