The South had more because it was profitable. It was not profitable for the North. They needed a different kind of labor. I believe money was the reason not morals.
I am not sure that is true. If it was not immoral for people to have slaves, then why would anyone in the North care? I don't drink urine, and I don't consider it immoral if someone does. I don't care if others drink urine. I think rape is immoral, and i think rape should not be allowed.
If slavery were not immoral to those in the North, then I don't see any reason anyone would spend time and energy on the debates about its morality. Make no mistake, the issue of slavery in terms of its morality was a massive issue before the civil war. Hell, Lincoln ran on an anti-slavery agenda backed by an anti-slavery party. They did not oppose slavery on the grounds that it was too profitable in the south but not the north, so I am not sure what you think the argument against slavery was.
North had slaves after the civil war. Lincoln only freed the Southern slaves leaving 500,000 still slaves in the Union border states, why? Even after the 13th amendment it was rarely enforced until years later.
Lincoln was vehemently against slavery, but he did not want conflict. Appeasement was always the goal of Lincoln before the war. In his first speech, he tried to reassure the South that he would not abolish slavery because he hoped it would smooth things over. He would have much rather let slavery die a slow death and avoid war. The whole reason he only freed some of the slaves with the Emancipation Proclamation was to get states who saw that the South would lose to come back to the Union so they could keep their slaves.
Lincoln tried to appease the south and not rub in anything. In trying to appease the south, he very likely made more bloodshed than if he had simply waged a full out war. The implications of either action are hard to see, but the main reason Slavery was held over was to not stir up more trouble. The south succeeded on the assumption Lincoln would try and abolish slavery. Lincoln literally had said he would not and had not even taken office when the South moved to succeed.
The south wanted freedom, but the freedom they wanted was the freedom to continue to enslave black people. People can argue it was about taxes and other things, but that is not true.
How can I make this claim? The answer comes from John McQueen, the U.S. Representative of South Carolina.
...
I have never doubted what Virginia would do when the alternatives present themselves to her intelligent and gallant people, to choose between an association with her sisters and the dominion of a people, who have chosen their leader upon the single idea that the African is equal to the Anglo-Saxon, and with the purpose of placing our slaves on equality with ourselves and our friends of every condition! and if we of South Carolina have aided in your deliverance from tyranny and degradation, as you suppose, it will only the more assure us that we have performed our duty to ourselves and our sisters in taking the first decided step to preserve an inheritance left us by an ancestry whose spirit would forbid its being tarnished by assassins....
So the idea that the Civil war was not about slavery is wrong. It might not have only been about slavery, but it was mainly about slavery.