How did new technology help focus the American economy on the production of consumer goods in the 1920's?

There were essentially two important factors in the expansion of consumerism in the 1920's.  First was the introduction of the assembly line to manufacturing. Henry Ford is advanced as the innovator of the assembly line by historians.  His use of the assembly line in the production of automobiles became a model for other industries.  The assembly line allowed more goods to be produced at a lower price. This is the very definition of efficiency, and allowed for greater profit and incentive. Another technological factor that expanded the supply of consumer goods was the improvements made to infrastructure, particularly in the area of transportation and communication.   The extension of telephone lines and the electric grid in the United States made it easier to conduct manufacturing.  Most companies moved away from coal and steam machinery and utilized electric machines. Electric machines were more efficient and cost less money. Transportation networks like highways and railways allowed goods to be moved easily over long distances to market.  While these infrastructure improvements happened as a result of a boom in manufacturing and not because of it, they allowed consumerism and industry to excel.