In 1913, the Ford Motor Company started using assembly lines to build their cars. Ford's workers could build a complete car in 93 minutes on the assembly line. Before then, it took workers many hours to build a single car by hand.
What happened to the overall supply of cars after 1913?
The supply went up. The supply went down.
Overall supply is the total amount of a good or service that producers make and sell. There are several things that can make overall supply go up or down. The table below shows how changes to these things might affect overall supply.
 | Resources | Number of producers or suppliers | Expected change in demand
Supply goes up | when resources cost less or are easier to get | when there are more producers or suppliers | when demand is expected to go up
Supply goes down | when resources cost more or are harder to get | when there are fewer producers or suppliers | when demand is expected to go down
Producers are people or companies that make goods or provide services. Suppliers are people or companies that sell goods or services. New inventions or technologies can also help workers produce goods and services more quickly. As a result of these changes, the supply of a good or service will often go up.
The assembly line was a new technology. The Ford Motor Company used the assembly line to build cars much faster than before. So, the overall supply of cars went up.