The prosperity that the US experienced after World War II changed the lives of ordinary Americans by making them much more comfortable than they ever had been before. It created more leisure time, doing so to the extent that a new “youth culture” arose among adolescents who had the time and money to spend on leisure activities.
During the post-war years, Americans came to have more consumer goods than ever before. First of all, many more of them lived in their own homes. The rates of home ownership jumped strongly after the war. Those houses were filled with more appliances than before. More people came to have washing machines, refrigerators, freezers, and vacuum cleaners. Perhaps the greatest symbol of the consumer affluence of this time was the television. There were only 7,000 TV sets in the country in 1946, all of them black and white. By 1960, there were 50 million sets in the country that were much more advanced than those in 1946 (source: Tindall and Shi, America: A Narrative History, 5th edition, p., 1427).
The children who lived in these homes were also more affluent than ever. As they reached adolescence, they largely did not have to work. They had the time to have fun and their parents’ money to buy things with. This led to the boom in the sales of things like records and record players.
In all of these ways and others (the car culture being an obvious “other”), Americans’ standard of living grew dramatically in the time after WWII.