A modern automobile is a four-wheeled vehicle designed for passenger transportation and propelled by an internal combustion engine powered by a volatile fuel. It is one of the most common of modern technology, a global industry with dozens of manufacturing companies producing millions of vehicles each year.

Invented and perfected in Germany and France toward the end of the nineteenth century, the automobile had a major impact in the United States in the early twentieth century. With its vast land area and a hinterland of scattered and isolated settlements, the United States had a great need for automotive transportation. Cheap raw materials and the American tradition of mass production enabled manufacturers to produce cars in larger volume than the small, integrated European factories of that time.

The automobile revolutionized many aspects of life in America. It made it possible for urban dwellers to rediscover the pristine landscapes of rural America, and for suburbanites to shop in towns and cities. Families could take vacations in new and exciting places, and young people gained more freedom to roam and explore as they drove away from home. The automobile also helped a variety of new industries to blossom, from road construction to rubber and steel, lubrication to vulcanized gasoline.

In addition, the automobile brought social change as well. Women took advantage of the freedom it offered, and some women even traveled across the country to campaign for women’s rights. These women, including Nell Richardson and Alice Burke, decorated their cars with “votes for women” banners to promote their cause.

The first automobiles were clumsy, heavy, and unreliable. But by the end of World War I (1914-18), Ford introduced the assembly-line process, which allowed workers to stay in a single position and focus on just one task as the car parts passed in front of them on conveyor belts. These innovations and other technical developments such as steel bodies and heaters improved cars’ handling, comfort, and safety.

Today, cars continue to undergo technical innovation. Electronic controls, airbags, and anti-lock brakes have made them safer. High-strength plastics and new alloys of steel and nonferrous metals allow for lighter, stronger, more durable cars. Hybrid engines have made it possible to use electricity when cruising, while a conventional gasoline engine takes over for acceleration and recharging the electric motor’s battery.

Automobiles have an enormous effect on the environment. Their impacts begin with the manufacture of all the parts and materials that go into a vehicle, and they continue right up to its disposal in a junkyard. Nearly 90 percent of the lifecycle greenhouse gas emissions from a typical automobile are associated with fuel consumption.

But the automobile is not just a consumer product; it is an indispensable social and cultural tool. It allows families to get out and explore the countryside, reintroducing them to pristine natural landscapes they had long forgotten; it brings suburbanites into town to shop and socialize; it enables teenagers to escape the suffocating confines of a public bus and find their independence; and it facilitates relaxed sexual attitudes among dating couples.