He resigned because he was accused of tax evasion and earning a lot of money that was not reported to the internal revenue service. It was believed that this money was made from controversies with various companies for road-building and architecture.
<span />
This is due to advances in communication
After the civil war there was a huge surge to rebuild the infrastructure of the U.S. many Americans wanted to move west to escape the horrors of the civil war, which started the race to the west coast (intercontinental railroad)
<span>African Americans left the South in large numbers to work in war-related industries.</span>
