A major development that took place in the 1920s in the US economy was the introduction of mass production. It was an important and notable feature of the industrial production of the country. Henry Ford had speeded up the production of cars using the assembly line system.

1. Henry Ford had adapted this idea from the assembly line system of the slaughter houses in Chicago. He had noticed that the slaughtered animals were collected through a conveyer belt by the butchers.

2. He then adapted this line into the production of cars. The idea behind this was that by the presence of a conveyor belt, the worker would work mechanically at an increased speed by doing the same work again and again.

3. This would also lead to the absence of any delay of work as the product would be in front of them at a conveyor belt.

4. This led to the production of cars only at a three-minute interval.

5. However, this also had a big disadvantage. With the increase in the work and necessary speed required to do so, many workers started to quit.

6. To retain the workers, Henry increased the wage to $5 in 1914. He also banned any form of train union.

This method of Ford soon spread to other parts. Since the cost had declined due to mass production, there was an increase in demand for cars by the workers earning higher incomes. The production of cars had increased from 2 million to 5 million within a span of ten years from 1929 to 1939.