It is funny how the ignorant of today believe they understand the mentality that existed up to the Civil War. As always, CONSERVATIVES rewrite history(or minimize what they do not agree with) to be of their liking and consistent with their present day agenda. 

From one article: Recall that in the "Great Compromise," it was determined that representation in the House of Representatives would be based on the population of each state. After the convention approved the Great Compromise, Madison wrote: "It seems now to be pretty well understood that the real difference of interests lies not between the large and small but between the northern and southern states. The institution of slavery and its consequences form the line of discrimination."

To imply nearly 100-years later(Civil War) what had been a monumental issue(slavery) in the creation of the USA was 
now reduced to the North telling the South what do as the motivating factor for fighting by the southern soldiers is absurd.