Well, let's stop at 70-year-old history on the way. At the end of WWII, the US had not been bombed nearly into oblivion, had not had large fractions of its population killed off, and had not been occupied (or ruled) by psychopaths trying to kill off everyone who wasn't like them. In the US, you could spend your time trying to build the future instead of trying to rebuild from the damage of the past. You also could live your life with less fear of a return of the days of killing. So, yeah, that looked a lot like opportunity in those days.

Today? That's less clear cut, I agree.