The Union used a large naval blockade to stop most of the South's cotton trade. I hope this helps!
John Brown stirred up a lot of controversy with his attack on "Harper's" Ferry in Virginia
The powerful nations of Europe were ready to formally expand their empires into Asia and Africa. Known as New Imperialism, this desire for expansion was motivated by many things, not the least of which were the promise of economic growth, the sting of national rivalries, and a sense of moral superiority.
The president gets his/her power from Congress.