Basically the text is explaining that the way Americans level of skill made them unequaled to the rest of the world (mind, that is not a fact because there was a large share of well-working people in the world in this time) . Also it explains that American brain and ability to construct (why is this entire article just bragging about Americans being so much better when that's not 100% true?) was one of the most economic boosting things and they were very productive for that timeframe.
That's my best understanding of the article. (Scholastic really likes to brag about Americans, huh?)
-Northstar