Automobiles are wheeled vehicles that carry a driver and usually a small number of passengers. They are powered by an internal combustion engine (gasoline, diesel or gas-electric). A car is typically constructed to run mainly on roads and can have four or more wheels. Vehicles devoted to the transport of cargo are called trucks/lorries or buses.

Although Gottlieb Daimler fitted a horse carriage with his four-stroke engine in 1886, Karl Benz is considered the inventor of the modern automobile. His Benz Patent-Motorwagen used a four-stroke, gasoline internal combustion engine to power his vehicle. Unlike bicycles, cars can seat one to seven people.

The Ford Model T is considered to have put America on wheels because it was a mass-produced automobile that ordinary working people could afford. The car was a major force in social and economic change as new industries developed to provide the materials needed for automobile production, and services like gas stations and convenience stores opened.

After World War II, market saturation coincided with technological stagnation; engineering was subordinated to the questionable aesthetics of nonfunctional styling and quality deteriorated. Automobiles were also perceived as a source of air pollution and as a drain on dwindling oil reserves. In the 1960s, American automobile companies were losing market share to German and Japanese manufacturers of fuel-efficient, functionally designed, well-built small cars. The era of the annually restyled road cruiser was ending as a new age of electronics was beginning.