Final answer:
The automobile became popular due to Henry Ford's mass production techniques, especially the assembly line, making cars like the Model T affordable for many Americans, which in turn supported a broader economic and social transformation by enabling mobility and altering consumption patterns.
Step-by-step explanation:
The popularity of the automobile was driven by a combination of technological innovation, economic factors, and cultural shifts. Henry Ford's implementation of the assembly line hugely reduced the cost of production, enabling mass production of cars like the Model T, which plummeted from an initial price of $850 in 1908 to just $300 in 1924. This made cars affordable for the average American, which in turn revolutionized social mobility and contributed to the rise of the middle class.
The economic impact of the automobile extended beyond lower car prices. It sparked a dramatic expansion of industries such as steel, glass, and rubber, and significantly grew the oil industry, necessitating a transition from coal to petroleum. New infrastructure such as roads, motels, and restaurants emerged to cater to a newly mobile populace. This physical mobility also resulted in the geographic freedom that altered residential patterns, moving away from the confines of rail-based city to sprawl into automobile suburbs.
The widespread ownership of automobiles facilitated by credit and advancements in mass production created an automobile culture, where cars became deeply intertwined with American life, influencing everything from infrastructure to city planning, and from economic growth to patterns of leisure and consumption.