Automobiles are four-wheeled vehicles designed to carry people and to be propelled by an internal combustion engine using a volatile fuel. During the first half of the twentieth century the automobile became a central force in American culture, the backbone of an industrial society that consumed vast amounts of steel and petroleum and was the largest customer of many ancillary industrial products. It also drove the development of modern manufacturing techniques and influenced the design and style of cities.

The modern automobile consists of a complex technical system, and many of its subsystems have specific design functions that must be fulfilled. These subsystems include the body, chassis, powertrain, and electrical systems. Automotive designers have used breakthroughs in materials and engineering to improve the comfort, performance, and safety of vehicles. They have also designed cars with more environmentally-friendly features, such as the use of high-strength plastics and alloys of both ferrous and nonferrous metals.

The first true automobiles were steam-powered and came into wide use in the 1890s and early 1900s. Invented by Nicolas-Joseph Cugnot of France in 1769, these heavy machines were often referred to as phaetons or vaporettos. A variety of manufacturers produced such vehicles, but their main disadvantage was that they required much time and effort to warm up and move.

A more practical and economical version of the automobile was developed by Karl Benz in 1886 with his Patent-Motorwagen. A few hundred of these were sold during the next two years, but they had limited driving range and were difficult to operate. Benz’s successors created more efficient and dependable models that were easier to drive.

By the 1920s and 1930s car production was booming, with companies such as Ford, General Motors, Chrysler, and others dominating the industry. When the United States entered World War II, production of passenger cars slowed down, but afterward new innovations made it possible to mass-produce cars quickly and cheaply. Automakers introduced new convenience features such as electric ignition and self-starter (by Charles Kettering for the Cadillac Motor Company in 1910-1911), independent suspension, and four-wheel brakes.

After the end of the war demand for automobiles again grew. Several companies that had been producing other products before the war, such as Toyota, Honda, Nissan, and Suzuki, began to produce automobiles in significant numbers. In addition, several European compact cars – most notably the Volkswagen Beetle – caused a sensation in the United States and started a trend toward smaller, more fuel-efficient cars.

Owning an automobile allows people to travel independently, without depending on the schedules of friends or relatives. It also provides freedom from having to follow the social distancing rules of pandemics or other health emergencies. For some, a car is a symbol of wealth and status, as well as an important tool for getting to work or school.