$1:
Many people would disagree with you on this point. The United States is very divided, maybe as much now, as during the civil war.
In the heart of American, you are labeled Liberal or Conservative. Liberal being the dirty word.
Civil War? I doubt it will come to anything like that. From what I have seen even though they may differ in ways to run their country in their hearts they are all Americans, citizens of the United States and share much in common with one another. That is why it is about life, liberty, and pursuit of happiness. It is a nation where people are free to decide their own destiny and that is why you will find a wide arrangement of opinions. I don't think it makes them divided but stronger for being able to differ yet call themselves the same people, Americans.