Well, when someone shows me some documentation that we are "going South" to free the slaves then I will believe that the war was over slavery. Lincoln himself didn't say it, he even offer the states a chnce to comeback and keep the slaves, they refused. He admitted West Virginia as a slave state, he overturned Fremont's emancipation, and even though he announced the EP, and we know how many slaves that thing freed, he admitted he did not have the power to free any slaves. These are not the actions of a president or an army whose sole purpose is to free the slaves.

GP