Automobiles are vehicles that use mechanical energy to turn their wheels and propel them forward. This energy could be chemical (in gasoline) or electrical (from a battery). The speed at which the wheels are turned is measured in kilowatts or horsepower. There are many types of automobiles, and each has its own characteristics.

The automobile was a driving force in twentieth-century America, creating new jobs and revolutionizing industries. By the 1920s it ranked first in value and was one of the top consumer goods, providing many jobs in steel, petroleum, and other ancillary industries. It also fueled a huge growth in other parts of the economy, such as road construction.

It isn’t clear who invented the modern automobile, but Karl Benz is generally given credit. He used a four-stroke internal combustion engine to power his Benz Patent-Motorwagen in 1885.

Until the 1910s most automobiles were built by hand and were mostly for wealthy people. But Henry Ford introduced a factory-based production system, lowering the cost of cars to the point where ordinary families could afford them. Other companies began to build cars in large numbers and the industry grew rapidly.

Automobiles opened up new opportunities for people, as they could travel farther and faster than before. Families were able to visit places they could not reach on foot, and towns could be linked together. Teenagers gained independence and freedom with driving, and dating couples could now meet outside the home. However, with increased traffic came problems such as accidents and pollution. The demand for licensing and safety regulation arose, along with concerns over gas-guzzling engines.