I'd say it was more about the manufacture of goods in the US for the domestic market rather than Europe.

Firstly, the Second World War. The United States under the presidency of Roosevelt had rapidly turned the economy into a war time economy. This was especially possible as during the Great Depression the President had expanded his powers and the government was 'Big'. Roosevelt's changes had a positive impact, and thus ideas such as isolationism and laissez faire had less support than in the 1920's. This made it easy for the government to transition the economy to war time in a short period of time.

The Second World War meant a demand for the manufacture of weapons, tanks, aircraft etc that would be exported to Britain, the Soviet Union, and movements in Europe resisting the Nazi's. The Lend and Lease Act allowed America to do this while staying neutral. This resulted in an increased supply of work available to the American People. When America formally entered the war more Women took the jobs that men who were soldiers would be doing.

Once the war was over, American soldiers were returning home. This led to a 'Baby Boom'. Thus, there was rapid population growth in the years 1945-1950. This led to the creation of new markets for babies e.g. toys, diapers. Then as Baby Boomers grew up to be children and then teenagers even more markets would open up such as cosmetics, cars etc.. People were spending lots of money on consumer goods which were back in demand.

Finally, the Presidency of Truman helped the USA's economy transition back to non-war time. The GI Bill 1945 helped veterans transition back into civilian life through education subsidies and training programmes. He was also tough on Trade Union Strikes, less strikes was good for the economy as services were less likely to be disrupted.