in what way did the nations growing transportation system help promote economic growth?
a. It made it easier for native Americans, and freed African-Americans to obtain the same goods as white people, boosting demand.
b. Because they added cost for the delivery of goods, it made more profits for the manufacturers.
c. Railroad debates and pools brought down prices for small farmers, who could then afford to modernize their equipment.
d. It opened up national markets for selling and obtaining resources and helped lower cost of production.