Quibble -- The US had some technical advantages, the Germans had it in other areas, but the only one that would have been overwhelming (a-bomb) wasn't available in the European / Med theater; by the time the US was engaging in combat with the Wehrmacht or Waffen SS, in N Africa, the attrition had been chewing away at the German forces, and the US was continuously building up everything needed. The Sherman tank wasn't a patch to the German armor, but the US built something north of 30,000 of them for the European / Med theater alone. By 1943 in Italy the tide had turned on their eastern front and the terrain became their best friend. By 1944 the collapse was on, their airforce was in tatters, and they were fighting a two-front war, and on their western front when threatened with being cut off, their soldiers were fleeing without their vehicles and armor. The US army did its usual fantastic job, but we should be grateful we were fighting them at the end of their strength.
And as an aside, I can't believe how close the Luftwaffe came to winning the Battle of Britain. Two weeks more but Hitler threw in the towel. Who elected that guy, their descendants must be the ones who voted for 0bama! ;)