Answer:
The federal government thrived the economy by imposing high tariffs to favor national companies, create grants to convince railroad companies to build a railroad net, and by removing native American settlements so the farmers and miners didn't run risks.
Step-by-step explanation:
First of all the U.s. the government carried on a nationalistic, expansionist strategy to thrive the economy. It imposed high tariffs on foreign companies so nationals were preferred over foreign ones. Also, because it created a land granting program to pay for the construction of a railroad net in species not in money. But also by erasing the native American settlements to profit their land. Thus, the reasons might not look as very complicated but the process of achieving them was really difficult, for example, the railroad companies didn't want to build a net, so they had to create a way to pay them for doing so.