The economy: an unfair portion of the debt from the Revolution had been put on the South. They were a little touchy on that score.
I have never read anything contemporaneous where southerners brought this up. It was 70 years in the past in 1860. Foreshortening of history causes 1860 to look closer to 1890 to seem closer in time to use than it did to those living then. It would be like regional resentments of today being based on things that had happened during WWII. It should also be noted that this "unfair" stuf took place under G. Washington's administration, a southerner. Southerners agreed to it in a bargain whereby they got the national capital in the South.
I should also point out that to people who are one bad harvest away from starvation, any tax cuts.
True, but the people in power in the South, the planters, weren't in that position. And I see no reason to believe northern farmers were any better off.
Citing slavery as the primary cause tucks everything away in a tidy box with two morally separate compartments. It lets people believe they’d never do a thing like that. But the problem is that it dehumanizes one and lionizes the other.
I quite agree. The issue was more complex than that. But that doesn't make the basic issue that slavery was the primary (not sole) cause of the war untrue.
Southerners faced the loss of their property and livelihood. There was also Bleeding Kansas, Nat Turner and Harper’s Ferry and the fear that their slaves would eventually outnumber them, acquire knowledge and arms and do what humans do. Paradoxical that, but characteristically human.
Unfortunately, here you undercut your previous claims. Protecting slavery was critically important to them for all these reasons and more.
Then there was the deluge of defamation and exaggeration poured out of the Northern press.
Often matched or exceeded by the vitriol headed North. Defamation and exaggeration was tossed around by both, and the hotheads on both sides eventually succeeded in polarizing the two sides sufficiently that was became almost inevitable. Up to around 1810/1820 both regions were generally in basic agreement on the subject of slavery: It's an evil, but we can't figure out how to get rid of it safely. Such a position lends itself to compromises of various kinds.
By 1860 the South was very nearly unanimous that slavery was a positive good, and should be extended in both time and space. That position cannot be compromised with their earlier belief, much less with the increasing opinion in the North that they didn't care whether slavery was ended safely or not, it needed to be ended whatever the consequences.
Should have been "Foreshortening of history causes 1860 to seem closer to 1790 in time to use than it did to those living then."