The other problem with making the Corwin amendment the linchpin of your position is that it totally ignores the decades long strife between free and slave states, and the fear of abolition that manifested itself in Southern politics prior to 1860.
A decade before G.E. Haynsworth fired the first shots of the Civil War, Southrons met in Nashville to consider secession. What was their reason for consideration of severing ties? It wasn’t tariffs, or New York shipping firms.
Let’s see what the members of the convention itself wrote in their official declaration.
“We, the delegates assembled from a portion of the states of this confederacy, make this exposition of the causes which have brought us together, and of the rights which the states we represent are entitled to under the compact of Union.
We have amongst us two races, marked by such distinctions of color and physical and moral qualities as for ever forbid their living together on terms of social and political equality.
The black race have been slaves from the earliest settlement of our country, and our relations of master and slave have grown up from that time. A change in those relations must end in convulsion, and the entire ruin of one or of both races.”
President Polk, himself from Tennessee, was angry that Southerners were undermining his efforts to reach a peaceful solution to the question of slavery at the time. He recalled in his diary what he had told his cabinet. “I stated that I put my face alike against southern agitators and northern fanatics and should do everything in my power to allay excitement by adjusting the question of slavery in preserving the Union.”
Alexander H. Stevens of Georgia wrote, “I find a feeling among the southern members for a dissolution of the Union-if the anti-slavery measures should be pressed to extremity…”
The Richmond Enquirer opined “The two great political parties of the country have ceased to exist in the Southern States as far as the present issue of slavery is concerned. United they will prepare, consult, combine, for prompt and decisive action.”
The Columbia Telegram wrote “…form a Southern Confederacy, in possession by force of most of all the territories suitable for slavery, which would include all south of the northern latitude of Missouri.”
https://www.americanantiquarian.org/proceedings/44806651.pdf
There are many more quotes I could provide but the intent was clear. In the minds of the Southern power structure the abolitionist movement was threatening the institution of slavery, and a growing desire to break away was afoot. The Wilmont Proviso had drawn particular ire and though it went nowhere it triggered a reaction. In the end the Fire Eaters were blocked at the convention by more moderate factions. There was no rebellion. That had to wait ten years, but in that decade tensions simmered until the election of Abraham Lincoln proved too much for the defenders of slavery to bear.
I have touched on this point many times before, and I'm thinking you either missed it, or didn't grasp it, or perhaps just refused to accept it.
There is more than one thing going on with the slavery issue regarding the strife between free and slave states.
The primary reason "free" states hated slavery is because they regarded slavery as competition for their exchange of labor for payment. The areas of the nation that are right now the hotbeds of Unionization, in those days would have regarded slaves as "scabs" who would take the bread out of their own mouths.
Yes, people have a deep and abiding hatred for the possibility of free labor undermining their wages and income.
The second main reason "free" states hated slavery, is because they hated black people. They regarded them as inferior and an abomination to normal society, and they wanted a society with no black people in it. Slavery brings black people into their society, and they did not want them. This is easily seen by looking at the northern "black codes" which were actually quite horrific in their unconcern about human rights.
The third reason why "free states" hated slavery was hatred of wealthy "elite" who owned the slaves, and therefore lived in luxury and did not have to work for a living. This same socialist style hatred of the wealthy is still geographically apparent in the same areas of the country that vote Democrat nowadays, and the same areas that voted Republican in the 1860s. Again, Geography and Demographics show the same pattern over time. Unionized (labor unions) areas of the country tend to vote for protectionism, strong government, government subsidies, and high taxes. They are the party of big government. Today they are Democrats. In 1860, they were Republicans.
The forth, and least significant reason for why "free" states opposed slavery was on the basis of being morally wrong. Only a tiny minority of people, mostly kooks in places like Massachusetts (which is still full of kooks today) cared about the morality of slavery. These people were seen as a minority of lunatics and mostly ignored, but this view of abolitionists changed over time when it became necessary to justify all the bloodshed caused by invading the South.
The propaganda organs of the North started portraying their motivation as a "moral crusade", because this has more power to sway the public than either a retaliation invasion, or an invasion to "preserve the Union." Everyone loves to get on a moral high horse and condemn other people when the "elite" crowd does it. We see this bandwagon effect over and over again throughout history. Global warming, Covid19 Transgender crap, Black Lives Matter, and so forth.
The "elite" declare a moral crusade, and the bulk of the stupid people simply follow along with it because they want to be thought "sophisticated" and of a like mind with the "elite."
But let us not fool ourselves into thinking this was their previous motivation. Their previous motivation was mostly self interest followed by intense racial hatred.
The abolitionists of the 1850s were about as popular as Animal rights activists are nowadays. They were a relatively small fringe minority.
Oh, I left out one more thing, and I believe it is the chief driver of all the organized strife between the free and slave states. That is *Control of Congress*.
The Northeast had gotten itself in the position of causing money streams from the South to flow through it's pockets, and they did this by some natural advantage in geography, but also through the usage of congressional power to pass laws favorable to their financial interests, and this is leaving out the subsidy laws they passed to favor railroad building, canals, and shipping/fishing subsidies.
Control of Congress determined if these money streams would continue as before, or get redirected back to the South.
The "Free Soil" party, which was one of the primary proponents in these free/slave fights, was headquartered in New York. I now believe it was an astro-turf sock puppet intending to disguise the motivation of New York interests in keeping the laws exactly as they were by preventing the Southern states from ever reaching a threshold of control in congress where they could overturn or change any of these laws that benefited the New York area.
Civil War history looks very different for me from what it once did. Once I started seeing the possibilities for corruption and ulterior motives, they became more and more obvious to me.
Perhaps all these things are just a coincidence and I am over-exaggerating their influence and impact, but they are mighty strange coincidences, because they always coincide with keeping the New York/Washington DC power base (same bastards still f***ing with us today) in control of power.
"Slavery" is just a smoke screen to hide their real intent, which was the continuation of power in their hands.