The Speaker of the House of Representatives would be next in line.
The battle between the USS Monitor and the CSS Virginia was significant because it was the first battle that used ironclad ships.
This battle, known as the Battle of Hampton Roads, took place in March of 1862. This newly developed technology had never been used in American warfare up to this point. There was no clear winner of this battle. However, it is remembered because it changed the way naval battles would be fought by the US military.
France went to war with Great Britan while America remained Neutral, this sparked some controversy with France and America. It caused diplomatic relations to shift. America insulted France, France got offended, America didn't want to go to war with France. When the US ambassadors tried to go talk to France's government, they were turned away
1) he helped us go through the Great Depression without him there would have been chaos
2) he helped us win WW2 and kept many Americans morale up
3) he didn't just talk, he acted on what he said
these all made him become one of the great presidents