One common theme is what is sometimes called 'American exceptionalism'. We have always believed (and still do) that the US is a special country, that God loves us more, that we have special rights above other countries. It started with the Puritans, with John Winthrop's speech about a 'city on a hill' and continues to this day.
Another theme was expansionism. From the earliest days, Americans wanted more and more land. The Brits fought with the French and Spanish for control of more of the continent. Then the American colonies wanted their independence so they could grow bigger, and wouldn't have to share the wealth with Britain. Part of the argument was that an island couldn't control a continent. Then, once we had our independence, then came the age of 'Manifest Destiny', the idea that we were just -destined- to take over the whole continent. We forced Spain to sell us Florida, we pushed the Indians off their land, we took more than half of what had once been Mexico. And to this day we spend more on weapons and military than the rest of the world combined, so we can project our power around the world.
We also have always worshiped the wealthy. This was another thing handed down to us from the Puritans who were Calvinists and believed that financial success is a sign of God's favor. We have never had a royal class or a nobility, but we have always believed millionaires and billionaires were the right people to guide us, to make our decisions for us.
