Answer: Francisco Sagasti
Explanation:
Westward expansion was a natural progression for the nation because the most powerful entities came from the East (England). It is only natural that they spread out and conquer/capture/kill/annihilate those in their way (the true Americans/Native Americans). In doing so they conquered a whole land and taught them their ways while spreading West.
Indians were pushed out further into the Great Plains, the war happened and more land was received