"If so much of Europe wouldn't have been so ravaged by the war and focusing on rebuilding, the prosperity Americans experienced at that time wouldn't have existed."
Nope, the American economy at that time was very insular. In fact, the U.S. went into a recession after the war because it had too much excess capacity now producing things that neither the American or any economy needed. It took until 1950 before gdp hit the same level as 1945 (figures adjusted for inflation).
Exports didn't start making up a big part of the U.S. economy until the free trade agreements after 1970. One of the things that caused the inflation during the 70's was the 60's. Johnson thought he could have guns and butter. It turns out you can, for awhile, until the extra cash in the economy caused it to overheat. Reagan, but mostly Paul Volker as head of the Fed, wrung it out of the economy....errr...but not the deficit spending, that increased under Reagan. The dot com bubble during the 90s soaked a lot of that up, and caused the budget to balance. Clinton had little to do it with. The bubble burst about 8 months before his presidency ended and thus ended Al Gore's chances to be president. The U.S. then went into a recession from the burst dot com and then 9/11 happened which depressed economic activity further.