Paine wrote “Common Sense” in 1776. As you may know, this was during the times of the revolution. “Common Sense” was a pamphlet trying to encourage colonists to go against Britain. To win independence. Paine was an extreme patriot and he also wrote other papers for the revolution. “Common Sense” was the most sold.
Mostly the reasons were economic. The country's economy was dismembered when it entered the great depression and they had to take care of that. The South used this to reinforce its values because nobody was bothering them since the great depression forced the government to move its focus on something else.
The deaths at the Battle of Shiloh that was more than 10,000 troops.