I think the non-native US population has some unique characteristics due to having been settled by immigrants. No matter how desperate the situation was back home, you still have to be a certain kind of person to leave behind most or all of the poeople you knew, and set out across the ocean. On the positivie side, I think this makes for a resilient and adaptible population. But I think it also makes for a population that is self-centered and lacks empathy for those worse off.