U.S. mass production of low-cost cars in the early 20th century gave the automobile far more impact in this country than it had anywhere else in the world.
And 1917, NADA's founding year, was an inflection point -- when a sprawling, restless, adolescent nation turned a European invention into a tool to reshape itself. Even as the United States entered a world war, Americans bought 1,880,269 autos.
The U.S. horse population wouldn't peak at 25 million until 1920, as Brian Johnson, an analyst with the financial services company Barclays, has noted. Still, horsepower was replacing horse power: 1917 auto sales were double those of 1915, six times more than in 1912 and 30 times higher than in 1908, when the Ford Model T debuted.
The United States came of age in the late 1910s -- from an isolationist country to a global industrial and military power, from an agrarian economy to a mobile society with more city dwellers than farmers.
Visions of personal speed shifted from kicking a horse's ribs to commanding full-throttle V-8s. As with all adolescents adjusting to adult bodies and abilities, progress was awkward and fitful.
In 1917, the U.S. government was struggling with war mobilization and urbanization. Debate raged over Prohibition and women's suffrage.