Answer:
It impacts the United States socially by giving them a sense of strong nationalism
Step-by-step explanation:
The borders expand impact the United State socially by "giving them a sense of strong nationalism."
This because the idea of expanding border or territory in the United States was established in on the belief that God supported the United States in civilizing other parts of the world, thereby making them think the United States country is special and ultimately, the citizens hold the pride of being part of such country.