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)
C. built a fantastic city in the Andes where stome masons fitted gigantic blocks of stone without using mortar.
"It is a free-market advocacy group" is a statement about the Peace Corps that is true.