Final answer:
The growth of the American middle class in the 20th century was fueled by increased job opportunities in management and clerical work, greater access to education, and a shift in consumer culture that emphasized leisure and material acquisition.
Step-by-step explanation:
The rise of a distinct American middle class in the post-war era can be largely attributed to various socio-economic changes. Corporations required a growing number of managers and clerical workers, thus expanding job opportunities and creating a burgeoning class of professionals. Increased access to educational institutions allowed for more individuals to gain skills and knowledge necessary for these middle-class jobs, fostering upward mobility. The subsequent rise in disposable income and leisure time led to an enlargement of consumer culture and an era of material prosperity.
Leisure activities such as stadium sports, theaters, and department store shopping became more widespread during this time. Big department stores like Macy's in New York became hubs for the urban middle class, promoting consumerism and providing employment. This mass consumption was facilitated by advancements in credit, including the birth of the credit card, leading individuals to spend more than save, with an underlying expectation of rising future earnings.
Education played a fundamental role in middle-class expansion, with college education becoming more accessible to the children of this class, ensuring their place within the professional sphere for generations. This period was marked by a mindset shift where material acquisition and enjoyment of life's pleasures became the cornerstone of the American Dream, with the middle-class evaluating work, consumption, and education to maintain or improve their social status.