Answer:
The most impact battle was the battle of Gettysburg
The main cause was the Stock Market Crash of 1929.
Nashville tenessee is correct
According to Albert Barnes, their mistake was that they didn't speak against slavery. Although many of them believed that slavery was against god and against the idea that god made everyone equal, they didn't do much against it out of many reasons, either they thought it was a necessary evil or they were afraid of the public reaction.
The Federalist Papers were written to convince Americans to approve the U.S. Constitution.
