The "boom" years of the 1920's were characterized by a growth in the use of Automobiles.
While looking at the history of the United States, the 'boom years' of the early 1920s were marked by a huge change in the way people traveled.
Personal transportation was shifting from horse-driven carriages to Automobiles, recently mass-produced by Ford.
At the time, the automobiles were a clear sign of growing economic might of the United States and the optimism of the early 1920s.
Answer:
Subsistence agriculture
Explanation:
The Second Agricultural Revolution led to a decrease in subsistence farming rather than an increase.
