How did Rockefeller and the Standard Oil Company get around laws that forbade companies in one state from underselling or doing business in other state?

They developed the idea of creating trusts.

was a long, primarily nonviolent series of events to bring full civil rights and equality under the law to all americans. the era has had a lasting impact on united states society, in its tactics, the increased social and legal acceptance of civil rights, and in its exposure of the prevalence and cost of racism. in the south violence and fraud in southern elections from 1868 to 1876, which had reduced black voter turnout and enabled southern white democrats to regain power in state legislatures across the south

it increase by 12% a year from 1812-1820