What is a big idea from 1800-1848 in US History?

When were the first plots of land for the village of seattle laid out? august 1848 april 1851 november 1851 may 1853

The formation of business monopolies in the late 1800s was made possible by the (1) effects of laissez-faire policies (2) passage of federal antitrust laws (3) elimination of the free-enterprise system (4) adoption of socialist economic practices

One of the most significant problems facing governments with low gdp is that a low gdp often results in