What was the most likely cause of this baby boom?

The most likely cause of the baby boom was a combination of factors including post-World War II economic prosperity, which led to increased stability and optimism about the future. Additionally, returning soldiers and their families sought to settle down and start families, boosted by government policies such as the GI Bill that facilitated home ownership and education. Social norms also shifted during this time, encouraging larger families as a symbol of success and stability.