Following World War II, the United States experienced an era of unprecedented prosperity and economic growth. Which factor contributed to this post-war prosperity?

Increase in the demand for goods and services.

Explanation:

World War II changed the world forever, not only the US. In economic terms there were three main factors that led to high American economic growth after WWII:

The Bretton Woods agreement that reestablished a more flexible gold standard where the US dollar and most international currencies were pegged to the value of gold. Keynesian economic theory had succeeded in getting the US out of the great depression, and the US government realized that an increase in government spending, specially the military industrial complex was vital to foster economic growth. American citizens regained a sense of national pride and changes in society affected consumers' demand for goods and services. Women were vital in the American war effort and earned a vital role in society. American middle class grew exponentially and their new tastes and needs increased total demand, the "keeping up with the Joneses" concept of living better and the increase in the birth rates (baby boomers).

Increased consumer demand for goods and services

Explanation:

The consumer demand at that time was very high because of the closed businesses in the europe and the only country that was safe was America. The only country that benefited most by war America because it reduced the great depression by 25% and that after war, the europe lost the trust of the investors and all the investors took their money to country that has innovation, good busines policies and the most important thing was Consumer demand. The GDP at that time increase to 50% within 7 years which show that the GDP was growing with higher pace due to consumer demand within America and from greater exports which was due to collapse of European companies after war.