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.

indigenous people north and south were displaced, died of disease, and were killed by europeans through slavery, rxpe, and war. in 1491, about 145 million people lived in the western hemisphere. by 1691, the population of indigenous americans had declined by 90-95 percent, or by around 130 million people."

nafta and the union are used as a trade between other countries these   organizations are used as spokes person for the country