The modern world is a very different place from the world that existed 50 years ago. Our knowledge of ourselves and our universe has increased, infrastructures have become globalized and technological developments have revolutionized the way we communicate with each other.
Basically, a citizen of the United States is any person who is in possession of the citizenship, which can be acquired by being born on the territory of the US or by being naturalized. The citizens, unlike other legal residents, can choose their representatives in elections.
A neutral person throughout the revolutionary war is a person who does not take sides and doesn’t fight war.