Answer :in the decades following the Civil War, the United States emerged as an industrial giant. Old industries expanded and many new ones, including petroleum refining, steel manufacturing, and electrical power, emerged. Railroads expanded significantly, bringing even remote parts of the country into a national market economy.
Industrial growth transformed American society. It produced a new class of wealthy industrialists and a prosperous middle class. It also produced a vastly expanded blue collar working class. The labor force that made industrialization possible was made up of millions of newly arrived immigrants and even larger numbers of migrants from rural areas. American society became more diverse than ever before.
The mountain ranges were natural barriers to invading forces and stopped people from coing into india.
A.Job specialization creates social classes.
C because the influence events are the one that know that are right