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 (in nominal dollars), and only 10,000 units were produced. By 1924, 2 million units had been produced at a 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 (1914-1918) had disruptive effects on car production, temporarily making resources more expensive as they were diverted to war efforts and became scarcer in the commercial market. Although World War I began in 1914, the United States entered the conflict in 1917. As soon as the war ended, the trend of improved productivity resumed.