What state was added to the Union when the Southern states formed the Confederate States?

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 does the term “escalation” refer to?

What is the term for a short statement about history that has not been yet been proved