Final answer:
The baby boom was preceded by the end of World War II, which brought back military personnel and created a sense of economic security and prosperity that led to an unprecedented rise in birthrates, resulting in the 'baby boom' generation.
Step-by-step explanation:
The precursor to the baby boom was the end of World War II. This significant historical event triggered a marked increase in the U.S. birthrate, lasting from 1946 until 1964. The return of military personnel, a widespread desire among young Americans to start families, economic security, and confidence in long-term prosperity contributed to the dramatic rise in births, resulting in the largest generation in the nation's history to date. The period of the baby boom saw an estimated 80 million Americans born, with the peak occurring in 1957, where one infant was born every seven minutes.
The baby boomers formed a distinct cohort that significantly influenced American society. They grew up in a time of prosperity and were the first generation with significant spending power, later redefining cultural norms as they aged. Furthermore, the strong post-war economy afforded families the opportunity to focus on raising children, with many women choosing to stay home or seek part-time employment to support 'the good life,' which included second cars, vacations, and college education for their children.