American Exceptionalism

Why are we such creatures of provencial nature? We make allegiances to our towns, our counties, our state, our region, our old haunts, our schools, our teams, etc. Is it simply because we don't see a bigger picture? Or is it our nature? All of the above divide us, and I haven't even mentioned "politics and religion."
Getting back to the idea of nature, depending on your cosmonogy, there would surface several "nature" explanations. But that is another post. Back to the point. Personnally, I have held that, while America is the best place in the world to live, it has plenty of faults. It has literally 2 histories. 1 is a history of democracy, kindness, giving, never-say-die attitude. The other is a bloody history of using religion to justify greedy expansion, rebellion, and all-around debauchery. I want to know both histories, always have. Bummer is, history is written by the winners, and the winners always candy-coat the thing. The losers are always sore-losers and shade it their way. How do you pick out the truth? Ultimately, you have to have your best guess. Here is an article that is one person's best guess. I found it interesting, but again, I am no slave or victim to what has happened in the past, so I don't feel some kind of collective guilt about what America has done. That doesnt' solve anything.
The point is, while I am glad I am an American, I want to be careful I don't try to rationalize everything Americans do.