Automobiles are self-propelled vehicles that carry people and goods. They usually have four wheels and an internal combustion engine fueled most often by gasoline, a liquid petroleum product. Developed in the late 1800s, automobiles ushered in a new age of economic growth and personal mobility. They brought prosperity to dozens of industries, including steel and petroleum production. And they shifted America from an agrarian society to a consumer-oriented culture.

The scientific and technological building blocks of the modern automobile go back several hundred years. In the late 1600s Dutch scientist Christiaan Huygens invented a type of internal combustion engine that was sparked by gunpowder. The first steam- and electric-powered cars could travel quickly, but they had limited ranges and required time to recharge. Gasoline-powered internal combustion engines soon proved to be the most practical and reliable alternative. The first successful gasoline-powered cars were built in the United States by the Duryea brothers and the Ford Motor Company.

In America, cheap raw materials and a long tradition of industrial mechanization encouraged early mass production. The nation’s vast land area ensured great demand for automotive transportation. And a lower level of income distribution and more equitable ownership opportunities than existed in Europe made the automobile a relatively affordable consumer good.

Until the 1920s, most automobiles were expensive, luxury items. But Henry Ford introduced the assembly line, which allowed the manufacture of many cars very quickly. By allowing workers to stay in one place and work on a single task while the parts passed by, he reduced production costs and made automobiles affordable for the average American.

After World War I (1914-18), automobiles became more user-friendly and comfortable. Seat belts and air conditioning became standard features in most models. Steel bodies became cheaper and stronger, while heaters and power steering became available. In the 1920s automobile ownership grew dramatically and became the lifeblood of a new consumer goods-oriented economy. By the middle of the century it ranked as the top industry in value of production and provided one out of six jobs in the country. It also was the main customer of ancillary industries such as petroleum and steel.

The ubiquity of the automobile has given rise to a number of social and environmental problems. Traffic congestion, air pollution, and exhaust leaks are major concerns. In addition, the high profits made by car manufacturers may come at a price to consumers in the form of higher prices and a drain on dwindling world oil reserves.

While the automobile has transformed American society, its influence is now waning. A variety of new technologies-the electronic media, the laser, and the computer, to name just a few-are charting an even more exciting future. The Automobile Age is fading into a new Age of Electronics.