The impact that the Railroad had on the relationship between eastern cities and the great plains was that through the Railroads, crops and grain were brought to cities in the East. At the same time, settlers were brought to farms in the Great Plains.
For the first two terms of Franklin Roosevelt's presidency, Roosevelt clashed with a conservative Supreme Court over his plans for the country's economic future.
Many believed at the time that much of Roosevelt's actions were unconstitutional and an impermissible expansion of the executive's power.
Roosevelt tried to respond to the Court denying him programs by trying to pack the Court.
Ultimately, court packing was unsuccessful but Roosevelt ended up getting the programs he wanted approved and the Court he wanted nominated.
The last frontiers to be mapped are the Polar regions. They were discovered something about between 1925 and 1935.
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