Artful Dodger: Great points, Dan.

Some of the historical reasons America has had relatively more abundance are:

1. Geographical isolation from European world powers, especially in America's youth when it mattered most.
2. More abundant, and more easily accessible, natural resources than any other country in history.
3. In more modern times, exploitation of the natural resources of Third World countries.

As to middle-class wealth, this is due primarily to the bit of socialism Roosevelt introduced into our system with the New Deal & thereafter. Your fathers could work down at the plant, work a 40-hour week, own his home, provide for his family. But something happened. What? Answer: Roosevelt's paradigm, mixing socialism & capitalism, has been dismantled one piece at a time.

I dare say that, had the U.S.S.R. grown up on North American soil while the U.S.A. were stuck with Eastern Europe & Siberia, Russia would have won the Cold War.