Nationalism is patriotic feelings and having pride in one's country.
American and domestic foreign policy during World War 2 were linked in that once America entered the war it had a significant impact on its economy. ... It was Hitler who declared war on the USA. Prior to that American domestic politics were dominated by the arguments between interventionism and isolationism.
The Gibbons v. Ogden court case in a nutshell:
Ogden had a monopoly on operating steamboats on the Lower Mississippi.
Gibbons, who had a federal liscence to operate steamboats, tried to start business there and was sued by Ogden.
The ruling was that Gibbons would be allowed to operate there, which gave precedent to federal law over state law.
