The correct answer is the development of levittowns.
After World War II, the American economy was extremely propserous. The GI Bill helped millions of veterans attend college and obtain professional, well paying jobs. Along with this, men many came home after World War II to marry their girlfriend/fiance after the war.
This spike in marriages lead to a demand for family housing. This resulted in the development of Levittowns. Levittowns are suburbs where the houses look almost identical and are mass produced. These relatively affordable houses allowed for the average family to purchase a home where they can raise a family. This helped lead to the baby boom generation.