What were the factors that transformed American economy from agrarian to industrial?

There are several factors that transformed the US economy in the 19th century:

- Acquisition of new territories, westward expansion and access to new resources;

- the construction of railroad networks from the East Coast to the West Coast that allowed fast transportation of goods;

- invention of new devices and products that had massive demand;

- increasing use of machines that replaced hand labor and large scale manufacturing which accelerated after the Civil War;

- credit facilities by investors and bankers for businesses;

- growing urbanization and rural migration to the large cities.