Actually, after WWII, in 1946, we went right back into the depression. Unemployment SKYROCKETED to almost 20%. Truman quickly pressed congress to gut the New Deal leaving only Social Security and that, along with the Cold War Defense expenditures, essentially changed America into it's post-war economic system, briefly returning to New Deal style policies under Johnson, which lead to a 15 year stagnation only to finally be fully gutted by Reagan, and supported by Clinton to lead to a 25 year run of unbridled growth.
Absolutely not. 1946 was a time of tremendous prosperity. Where on earth are you getting your revisionist unemployment figure? GNP figures, ignoring government spending on the military, rose tremendously in 1946. Total GNP figures declined due to military spending, but that matters not. Unemployment rose slightly in 1946, when the million of men that were drafted returned home, but only to 2.6%. All empirical data was obtained from Robert Higg's study:
Wartime Prosperity? A Reassessment of the U.S. Economy in the 1940s: Newsroom: The Independent Institute
This flies right in the face of Keynesians, like Paul Krugman, who says war is good for the economy. I hope no one actually listens to him, lest WWIII is started.