What did the Civil War decide about the relationship between state governments and the central government?

Which sentence best describes the effect of the bill of rights

How was rockefeller able to build his monopoly across the oil industry? he found newer and cheaper ways to refine oil, increasing his profits. he confined his business to ohio so he could buy all the refineries there. he bought up oil refineries, cut costs, and reinvested his profits in other refineries. he began to sell kerosene as well as oil, expanding his market.

What was the plight and fight of the following groups? labor farmers native americans african americans women immigrants ~ ap u.s. history (period 6: 1865-1898)