I actually agree with you that biggest bone of contention is that the fire eaters in the south believed they could just vote to leave the Union. Though there were many southerners that wanted to stay in the Union.
Many in north did not believe that a state (not just the southern states but any state) could just vote itself out of the Union. Though there were some northerners who wanted to let them go.
Neither side would budge, so the war came. However, you have to ask yourself why the fire-eaters seceded? What was it about the election of a Republican to the presidency that cause this. (Remember they threatened to do this if Fremont was elected as a Republican in 1856.) I think if you research why the southerners called Republicans “black Republicans” or called Lincoln “Ape Lincoln” you might find out why they seceded. Or you could just read there secessionist declarations.
And why would they not believe this? The vast majority of the evidence indicates they could, and beyond that, most of the people believed they had the right to leave if they wanted.
Though there were many southerners that wanted to stay in the Union.
This is true, but in most of the Southern states, they were a minority. Missouri went the other way, but i've read this was because of physical interference by military officers, and if given a fair chance to vote on it, might have voted to leave.
Many in north did not believe that a state (not just the southern states but any state) could just vote itself out of the Union.
Very likely they believed this because they were told this by people they respected, though I don't know on what basis they could believe this from any historic documents or evidence. (Other than that letter from Madison.)
Though there were some northerners who wanted to let them go.
Horace Greeley, for example.
Neither side would budge, so the war came. However, you have to ask yourself why the fire-eaters seceded? What was it about the election of a Republican to the presidency that cause this.
I can only speculate. Discerning the truth when everyone is out to mislead you is not always easy. No doubt some of them (wealthy elite) worried about the possibility their slaves would eventually be taken from them, but more likely they were worried about a loss of power and influence. Most of the time, I have always found it useful in analyzing people's motives to look at the money situation.
Why do people support big government? Because they are getting money out of it.
There were social reasons as well. Many people in the Northern states had been haranguing them for being "evil people" because of the slavery issue, and this spilled over into a lot of other interactions between the two groups. They came to mock each other and hate each other for reasons beyond just their respective social environments.
I think if you research why the southerners called Republicans black Republicans or called Lincoln Ape Lincoln you might find out why they seceded.
I've read some of that, and I think they did it because they thought it was effective. Most people today remain unaware that the white people of the Northern states hated blacks equally, if not more so than did the white people in the South. Illinois "black" laws are horrifying and completely unfair. The same is true of other black laws in other Northern states.
Worst massacre of blacks in this era took place in New York city during the draft riots.
Or you could just read there secessionist declarations.
I have. Out of all of them, only three, perhaps four cite slavery as a significant reason for their secession. Should they be taken at their word? I don't know.
A few weeks ago I read an idea from Paul Craig Roberts of which I had never previously heard. His explanation asserts that they wanted out because of the taxes, but had no legal justification for leaving on the basis of taxes levied by the Federal government. Taxes were completely within the power of the Federal government under the US Constitution, and so long as they remained part of the Union, they had no choice but to pay them.
But on the other hand, the Federal government was not enforcing constitutional provisions regarding slavery. Roberts asserts that they were using this as a strictly legal argument that the Northern states had violated the constitution and therefore broken the compact because they refused to recognize or enforce constitutional protections for slavery. His reasoning is that by arguing that the Northern states had broken the compact, they had the legal right to abrogate the entire compact.
To sum it up, Taxes were their real bitch, but slavery was their legal argument to justify secession.
I don't know if this is correct, but I'm not quite ready to throw it out as nonsense. It sounds too conspiratorial and unwieldy, but who knows what the movers and shakers of a society discuss among themselves when they get together.
I see evidence of collusion between the "Deep State" of Washington DC, and the Media elite of New York, and so stranger things have happened. I should not be surprised if powerful Southern men engaged in collusion in the 1860s.