The Civil War was not about or because of slavery. The issue of slavery was simply the last straw that broke the camel's back so to speak. The succession of the South was bouund to come about some time. Abraham Lincoln just decided to use the war as a means to set the slaves free. Yet, it took him years to decide to finally do it.
I agree slavery was only the botton issue not the sole cause.
However Everything I have read about Lincoln leads me to believe when he freed the slaves he was doing more because he thought it would help in the prosecution of the war, and not because he necessarily wanted to free the slaves.
He actually announced it well before he put it into effect, He gave the southern states an ultimatum. Return to the union or I will free the slaves. Obviously they said FU and fought on. I have also read a lot about how Jefferson Davis actually toyed with the Idea of Offering freedom to slaves who would fight for the south.
Another interesting thing about the war, is many of the issues that the south did not like about Lincoln and the north, ended up being implemented by Davis. For instance Davis also suspended habeas corpus as Lincoln did. In addition the Confederacy actually was set up with even more central control than the US government had. For instance the Government of the south controlled the Cotton trade, and regulated the economy strongly.
To say the war was simply about slavery is naive. It also leads one to believe that the Northern people were tolerant of blacks while the Sountern folk were racist asshats. The truth is most whites were racist at the time. That includes the North. They just didn't believe in slavery, and the North (being far more industrial) didn't need need slavery for its economy like the South did.
Very true, even most Abolitionist while wanting to end slavery were not so keen when it came to the issue of equality among the races. In addition I would point out that only 1 in 5 southerners were slave owners. Most people in the south who fought did so to defend their states, and their land, from what they saw as northern aggression.
Clearly the Civil war is not as simple as a war about slavery. It was indeed about states, rights, and IMO forever answered the question about if states can leave the union or not.
Lincoln often argued that if he allowed the south to leave the union where would it stop. He said soon other states would leave that union, and than counties and cities would start leaving states. He felt it would end in Anarchy. Lincolns principle reason for prosecuting the war was as he said, to prove that the majority does rule in a democracy and that a minority can not just break the union when ever they are not happy with the way things are. He often spoke of how the US was the only real example of democracy at the time, and he felt allowing the union to be broke would send the message that democracy was a failure.
IMO while Lincoln trampled some rights, and bent the constitution to fight the war, I am glad he did it. Because if he had not, we would not be what we are today. Who knows where it would have lead, and where the dividing would have stopped.