What are some causes and effects of rapid population growth between 1900 and 1945?

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.

How do you believe the japanese justified their imperialism in korea taiwan and china

What would be considered a secondary source about the assasination of abraham lincoln