It means from coast to coast, across the entire country.
By passing laws to create the Supreme Court. by establishing the three branches of government. by passing laws to regulate commerce. by establishing the offices of President and Vice President.
Many of the maps we have are now digital. We could probably have holograms of maps in the future maybe.
The Voting Rights Act of 1965 removed barriers to black enfranchisement in the South, banning poll taxes, literacy tests, and other measures that effectively prevented African Americans from voting.