America is Good because of how it started. Men came from all over all at once and were generally okay with each other. The harsh winters taught them empathy for a new neighbor who wasn't used to the cold. Those who tried to take advantage of their neighbors were simply left to fend for themselves, neither punished nor prized. Those who lamented over their miserable lot in the unforgiving land, those who made sure everyone knew about their ancestor's riches or even their supposed fame in their old countries, and who insisted that they deserved something better, but who then refused to work on account of this supposed status, received little sympathy. The neighborly helping hand went to those who could show they were trying their damnedest.
The northern states didn't start on a foundation of slavery (specifically) and hierarchies (generally), and this old world model of society brought to the South eventually lost out. The northern states, which set the standard for the America of today, were populated with people who didn't see hard work as a representation of poverty, but as the only respectable road to wealth. Americans have always felt a certain disdain for the communities that keep their women in white gloves and try to put on airs, the people who “live like mice in their own kitchens.”*
The Americans that give the country its strength today are the ones who do not evaluate their neighbor's worth based on his parents' name or notoriety, but only on his own acts, because they, too, had seen family members succumb to winters of various shapes and sizes and wish, too, to be judged only on their own merits. Someone becomes successful in America almost never by luck, but by taking the right risks and by embracing the idea of hard work. That means that even the best “breeding” can produce failed adults if that adult makes the wrong decisions, and, likewise, there's no reason to be sure that someone from the wost of beginnings can't eventually make a name for himself. There is a respect for roads less traveled, for those who get what they want in the way that works best for them, even if it takes a little longer or requires a few stops along the way (provided, of course, that this method doesn't require hurting other people in the process).
America is Good because it takes cultural change in stride and it does not hang on to outdated ideas of caste and bloodlines. The first Americans never stopped telling their children of the humility that is gained during a months-long boat ride across an icy sea. The boats have also yet to cease their voyages today, and for this reason the stories stay fresh. America is Good because, even though it can take a little reminding sometimes, Americans never forget each other, and the fact that the happiness of one depends on the happiness of everyone. We always see ourselves in the faces of our neighbors, and this makes it possible for us to grow together.
*A quote from My Ántonia. Have I inspired you to read it yet?
I know this was totally optimistic and idealistic but that's how the book made me feel.