Source: Case File of Henry Ford, Committee on Science and the Arts, 1928 Cresson Medal.
In the early stages of their diffusion, automobiles were essentially assembled by hand, making them very expensive and affordable only to a small (wealthy) segment of the population. As the production efficiency of the assembly line was improved by Ford (among others), the cost of an automobile was substantially reduced through a division of labor and economies of scale. When the Ford Model T was introduced in 1908, it cost about $950 (nominal dollars), with only 10,000 units produced. By 1924, 2 million units were produced at the cost of $300 each, making it one of the most mass-produced cars in history, with a total of 16.5 million units. World War I had disruptive impacts on car production, making resources temporarily more expensive. As soon as the war ended, the improved productivity trend resumed.