Automobiles are self-propelled vehicles capable of sustaining motion without the need for external motivation (such as horses or electricity). A modern automobile is typically powered by a liquid-cooled, piston-type internal combustion engine that may be either gasoline or diesel fuel fueled. Its power is transmitted through either the front wheels, the rear wheels, or all four wheels; most passenger cars use rear-wheel drive systems.
Automobiles came into widespread use in the first half of the 20th century, allowing people to travel greater distances than ever before and change their lives for the better. Industries and jobs sprang up to meet the demand for automotive parts, fuel, and services. People could now move from one part of a city to another and pursue new work opportunities. They were no longer confined to a single home or workplace and could live farther away from their family members. Ownership of an automobile also helped people get loans to buy houses, since it demonstrated that they could make regular payments on a loan.
The automobile revolutionized American life, allowing women to work outside the home and become involved in politics and business. Women drove their cars around with “votes for women” banners and other messages during the 1910s and 1920s to advocate for suffrage, which eventually led to the 19th Amendment to the Constitution in 1920. Today, automobiles are made in the millions each year for consumer and commercial purposes. Most are powered by internal combustion engines, but hybrid and electrical cars are becoming increasingly common.