Gasoline-powered, internal combustion engine-propelled vehicles had been around for more than a quarter century by the start of the 1920s, but not until that decade did they become a central factor in the everyday lives of ordinary Americans. Mass production, together with innovations in design, engineering, manufacture, and sales, brought a new or used car, truck, or tractor within the reach of most people. In 1920, barely one household in three possessed a car, though this represented a dramatic increase from one in thirteen at the outset of World War I. Automobile ownership tripled during the 1920s, and by decade’s end, four families out of five owned one. By 1929 almost 27 million cars were on the road, in the driveway or parking lot, at the gas station or repair shop, or, increasingly, stuck in traffic. Meanwhile truck and tractor registration tripled as well to 3,550,000 trucks and 840,000 farm tractors. Outside the impoverished South, car, truck, and tractor ownership was fairly widespread and evenly distributed. According to a 1927 survey, 54 percent of families in cities over 100,000 owned a car, while 60 percent did in towns under 1,000; farmers were even more likely to have a car or truck. In less than a decade, motor vehicle ownership had gone from being unusual to being commonplace, and American daily life was thereby transformed.