What was the primary reason for the economic boom that occurred in the United States after World War II?

The economic boom following World War II was the result of pent-up demand.  During the war, most production was directed to the war, weapons and ammunition, uniforms for soldiers, vehicles to move troops. For example, no vehicles for private consumption were produced during the entire war.  This meant that after the war was over, production of consumer products could resume, and people were more than ready to buy cars, appliances, and clothing.  At the same time, soldiers returning from war were getting married, settling down, and having children.  This meant there was a need for new housing. There was a dreadful housing shortage during the war, and I know that my own parents were thrilled to find a studio apartment to start their marriage.  Various programs for benefits helped returning soldiers to purchase their homes, and educational benefits allowed them to go to college.  This generation, having fought a war and done without for so long, was ready to consume!
http://www.loc.gov/teachers/classroommaterials/presentationsandactivities/presentations/timeline/postwar/