Cars were invented because people were interested in seeing whether or not they could build a vehicle that could make travel easier. As early as the 1700s, European engineers started to play with the idea of creating motor-powered vehicles.
Once the mid 1800s hit, engineers had already attempted steam, electrical and combustion motors. In the 1900s, the automotive industry began using gas-powered engines. The first automobile that was produced for the population in the United States was the Oldsmobile. It had a three-horsepower engine and a curved dash. There were 425 of these vehicles sold in 1901 and then 5,000 in 1904. Demand was growing and would continue to grow.
Cars then became useful for those in the transportation industries and helped to move goods from place to place. When cheaper models came out, the middle class rushed to get these vehicles in order to have the freedom to travel. Cars also allowed people to choose to move away from railroad stations since they could always travel via car to get there.
Interestingly, the initial roads that were built were actually built for bicycles. These roads were often more narrow and did not have a lot of room for multiple vehicles. To combat this, highways were built and road systems expanded in western countries.