Without seeing your history book/knowing your material you're working with, I would say because the U.S. was a small nation of mostly poor people who had beaten a very wealthy, powerful nation with a much larger army in a war and had gained our own freedom and started to govern the way they wanted to-who had come to start their own nation in the first place because of what they felt was not enough freedom in areas like religion, and they had gotten what they wanted.
