So I've tried my best over the years to find an unbiased way to view the American Civil War but I've found it difficult. My two main sources of information on it throughout my life have been history class, and my grandfather (who was a very smart man who worked in intelligence at the pentagon and was fairly well read on American history). The problem with the first is that I have found obvious biases in my American history books, namely things like glorifying Sherman's run through the South and overlooking all the really shitty things he did. The issue with my Grandfather is that, as brilliant as he is, he was also heavily biased. He was born and raised in South Carolina and later moved to Virginia and would always tell me that the whole issue was about states' rights and that's that, which I have a really hard time believing, but I'm willing to believe that that's probably what he was taught and brought up with.
Slavery, obviously, was much more prevalent in the South what with the tobacco and cotton trades being so big down there but that doesn't really mean that there weren't slaves up north or even that people up North were these humanitarians who didn't see color. Growing up as I did in Pennsylvania you can see that people not being forced to interact with black people all that much just allows them to keep close to their chest and unadulterated their racist views and stereotypes. I can't imagine that people who were still so racist in their own right (and for so long after the civil war, too) could've possibly fought the whole damn thing because they cared so much that the South had slaves.
If it really was just about Slaves, was it seemingly from a humanitarian-, "all men are endowed by their Creator with certain unalienable rights"-perspective, or was it a thing of economics? I seem to remember a theory (or maybe a fact?) from American History that Lincoln freed the slaves in an attempt to cause unrest in the South, not out of the goodness of his heart. And I certainly remember that before the war, the North had placed heavy taxes on the South for the importing of finished goods from Northern industry, which is, I gather, the sort of action where terms like "War of Northern Aggression" comes from.
On a related note, was there a massive disparity between what the leaders of the war believed in and what your average soldier did? Did Jefferson Davis and Joe Virginia hold the same ideals? Was Lincoln actually a humanitarian's wet dream and as a result did he have to use some other kind of anti-South propaganda to convince pro-Slavery Northerners to fight in the war? If it wasn't about Slavery, why did the Northerners fight in the war?
So, AskHistorians, is it even possible to find some sort of objective reason for the American Civil War's initiation? Is the Southern or the Northern history text book more right? Or are they both wrong?
I'm drawing from another answer I gave on the topic. Hopefully this will explain the situation in the South leading up to secession and the factors that motivated southerners to secede.
In the three decades prior to the Civil War, a heady feeling best described as Southern nationalism - the idea that the South constituted a natural if not a legal nation, distinct from the rest of the United States in culture, traditions, manners, et al - had taken root in the breasts of many southerners. This nationalism formed largely in response to renewed northern criticism of the South, and especially of the institution of slavery. This anti-slavery agitation, unfortunately, came hard on the heels of the Nat Turner Revolt of 1831, when rebelling slaves killed several dozen white Virginians, and this event, along with example of Haiti, exerted an oversized influence on white southerners.
By the late 1850s, the majority of the white South was living in a nightmare world. It was widely assumed - you might say it had entered the southern mythology - that blacks were genetically incapable of self-management and could not be trusted with any degree of freedom. The particulars varied from writer to writer; a "benign" slave owner (and there were a TON like this, probably many times more than there were cigar-chomping sadists) who legitimately thought he was performing a Christian duty by "taking care of" his enslaved people might defend slavery by arguing that the low intelligence and slothful nature of blacks would render them utterly incapable of feeding and clothing themselves without the guiding hand of a kind master. A more brutal person might claim that the intemperate nature of blacks, combined with their laziness and bestial nature, meant that they were predestined to turn to violence and theft and became a vast horde of marauding brigands. Still others argued that freedom for the black man meant ruin for the poor white man; that ex-slaves, accustomed to living meanly, would work for far lower than a white man would. Regardless, they virtually all agreed that blacks had to be utterly dominated by whites, and the most efficacious means of accomplishing that was through the perpetuation of the master-slave relationship.
The Deep South believed that, whatever Lincoln might say, the North intended to act against slavery. The prospect of abolition was viewed not only as a potential economic disaster, but as a looming social catastrophe that would utterly sink the South. Three apocalyptic scenarios were widely bandied about. One, a genocidal race war might ensue, in which whites would be forced to kill blacks en masse or be themselves wiped out. Two, whites would be forced to abandon their homes and property and flee the region. If neither of those happened, the third and most viscerally terrifying possibility was that black men might rape or, even worse, marry large numbers of white women.