And why do these things always seem to develop in states with heavy port traffic and much contact with foreign nations and ideas?
Midwesterners out on the Plains may not have had much in common with New Yorkers, but they had no more in common with Virginia or Mississippi planters.
The vast majority of the populace out of the South was not Planters. They were just ordinary folk like those in the Midwest. Socially the groups of states I showed you would have all grown together over time and become a more or less similar voting bloc without efforts to keep them separated artificially.
had a common culture for a century after the Civil War and had more in common with each other than they did with the Southern states.
After the civil war, the Southern states were impoverished and many were desperately trying to get on their feet in the midst of crushing poverty.
I am referring to what would have happened in the absence of a war. The Southern population would not have been destitute and would have had similar incomes and concerns as the rural Northern populations, and they would have grown together in absence of war.
If New Orleans transformed itself into the great commercial capital, wouldn't far away farmers resent its power?
Oh absolutely. It is in the nature of man to resent and envy wealth. However, the wealth of New Orleans would have also been commensurate with an increase of wealth of these farmers because their dollars would go further without the protectionism instituted to protect the Northeastern manufacturers.
You don't really live in today's America, do you? There's a metropolitan culture in New York City or Los Angeles or San Francisco or Chicago, but it's also in Atlanta, Houston, Charlotte and other big metropolitan areas.
It is a sickness of big cities and concentrated wealth. Alexander Tytler pointed out that it is part of a much larger cycle of which most people are unaware.

And as I've pointed out, those were African-American slaves. Native Americans had been enslaved under the Mexicans, the Spanish, and the pre-Columbian Indian civilizations. Probably there were still some Indians who were essentially enslaved even under US rule. The region wasn't inhospitable to slavery and probably would have adapted to African-American slavery if the Confederates had taken over.
They had the opportunity to do so for half a century, and yet they did not. Therefore they would not.
Where slavery was legal and slaveowners controlled the government, uses would be found for slaves.
You are ignoring the economics. Unless a "use" could be found which would pay better than cotton farming, people would put their slaves into cotton farming. It's about money. People want as much of it as they can get with as little effort on their own part as possible.
I believe the Confederate Constitution protected the right of slaveowners to take their slaves everywhere.
As did the US Constitution, though it had been deliberately misinterpreted in such a way to give states the right to overrule the "privileges and immunities" clause in the case of slaves. I think the US Constitution was never intended to be interpreted in the manner it was when it was written, but we've seen the misinterpretation play over and over again in Liberal strongholds.
The Southern constitution simply made the point explicitly.
You've said Northerners hated Blacks and didn't want to live among them and have to compete with them. If true, that's all the more reason why they'd want a national border between themselves and the South.
A border is just a meaningless line. (as we are now seeing with our own southern border.) It won't keep people out, only proactive measures will do that.
The economics would have moved states to join the South, and those advantages would have overcame a lot of reluctance in other areas.
Again, it would have started with the borders states like Missouri, Kentucky, Tennessee, Maryland, etc.
That's an indication of where the modern world is headed. Out of the way rural areas aren't much affected. If you want to form your own country and develop it into an economic powerhouse, those changes will transform your culture and society. Examples are Ireland, Quebec, the American South today, and the United States itself. Wealthy countries form their own elites, and those elites look for things to do. I suppose a new country could resist becoming wealthy and an elite could cut itself off from the world and move in the opposite direction, but those aren't necessarily better options.
The vast majority of the populace out of the South was not Planters.
The planter class was crushed by the war. Had the war not happened, they would have been ruling for a long time. This would not have been acceptable to the midwestern states. Take the time if you have it to look up what South Carolina politics were like before the Civil War. That is not something that would be appealing to any people with free and democratic traditions.
I am referring to what would have happened in the absence of a war. The Southern population would not have been destitute and would have had similar incomes and concerns as the rural Northern populations, and they would have grown together in absence of war.
You apparently still think that the 2004 election was the template for all American politics. But it took time for the Southern and Plains states to come together politically. The South had to get rid of slavery and segregation. The planter elites had to be displaced. Corporations and industry had to move in. Air conditioning had to be developed and made common.
The Germans and Scandinavians of the Plains had to become assimilated and lose their European ways. Southerners a century and a half ago didn't much love the Germans. Neoconfederates today are forever maligning them as early socialists, wrongly but not entirely without reason. All that would have to change, and as recently as half-century ago, the Upper Plains were more Mondale, McGovern, and Humphrey than anything else.
Oh absolutely. It is in the nature of man to resent and envy wealth. However, the wealth of New Orleans would have also been commensurate with an increase of wealth of these farmers because their dollars would go further without the protectionism instituted to protect the Northeastern manufacturers.
Tariffs weren't the big determining factor that you believe they were. Moreover, tariffs only went up as high as they did because of the necessity of paying for the war. And they only stayed up as high as they did because the Democrats had become identified as the party of rebellion. American politics is a dynamic system, and barring some catastrophic event -- the Civil War, the Great Depression -- the two parties tend towards equilibrium. Had their been no war, the two parties would have competed on more even terms and protectionism would have been less of a reality and less of an issue. If farmers were discontented, they would work within the political system to redress their grievances, something Southern planters didn't want to do.
They had the opportunity to do so for half a century, and yet they did not. Therefore they would not.
There were only 13 years between the Mexican Cession and the Civil War. Arizona and New Mexico were sparsely settled in those days and wouldn't become states for another fifty years. Forms of slavery had been around in the area for centuries, and given a pro-slavery national government, slavery would have continued and been expanded.
A border is just a meaningless line. (as we are now seeing with our own southern border.) It won't keep people out, only proactive measures will do that.
What we are seeing now is a special case. Most of the time active measures are taken to secure borders and control border traffic. Most of the time, borders more or less work if you want them to. But you don't really answer my point here, which is that if Northerners had no great love for African-Americans, they would appreciate a national border keeping them out.
Of course, it's pointless to argue about counterfactual history. We will never know what would have happened if things had happened differently. There are too many factors involved to be able to say anything with any certainty. Given the complexity, I don't see how anyone can have the confidence in their own predictions that you have.