Destruction had nothing to do with it. What was destroyed in the US?
WW2 put the country to work...building ships, airplanes, tanks, bombs, guns...and other war stuff. I think that is what is meant by the universal opinion that WW2 brought an end to the Great Depression.
The national workforce was mobilized working for the war effort.
Not only that, but who in the world (besides the USA) had a standing infrastucture and operating factories to produce stuff after WW2?