What explains the United States rise to the industrial and economic importance in the late nineteenth century?

the railroad industry led to the development of other processes.

Explanation:

Having refrigerated train cars allowed meats to distributed throughout America, allowing the agricultural economy to benefit, ultimately enabling the US to profit. It also created a whole new industry, creating more jobs in certain cities. Those cities had to create housing etc to accommodate the influx of people coming in for jobs.

it took two men to wrestle rome back from chaos and turn a republic into an empire. in the first century bc, rome was a republic. power lay in the hands of the senate, elected by roman citizens. but the senators were fighting for power between themselves.

geography

this is because warmer climates often don't get people sick from the flu and regions where it was often colder more people received the flu. hope this if you need more reasoning i am here to