While suburbs had originated far earlier; the suburban population in North America exploded during the post-World War II economic expansion. Returning veterans wishing to start a settled life moved en masse to the suburbs. Levittown developed as a major prototype of mass-produced housing.
In the U.S., 1950 was the first year that more people lived in suburbs than elsewhere. In the U.S, the development of the skyscraper and the sharp inflation of downtown real estate prices also led to downtowns being more fully dedicated to businesses, thus pushing residents outside the city center.
Here is a little film by Redbook from 1957. I hope you enjoy it!