The turning point in Greek history was the Trojan war in 12th century
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.
It is important because the French regained the high ground
So he could make peace through out the land.