Slavery is a great evil, then, now, and forever. Nevertheless, antebellum American plantation slavery, where the overwhelming majority of persons in chattel bondage were held, was focused on cash crops like tobacco and cotton, and not on feeding the populace.

Slaves were used to grow rice (South Carolina, Georgia), sugarcane (Louisiana), corn (Virginia, to Mississipi), wheat, and vegetables (sweet potatoes, beans, okra, collard greens, squash, cabbage etc)

They were used in cattle ranching and hog husbandry. They worked as butchers and meat processors. In places like the Chesapeake Bay region enslaved individuals were involved in oyster harvesting and processing.

The division of the US into slave and free states produced an increasingly stark prosperity contrast between the two. That disparity underlay the friction between the two groups.

Quite. It was very noticeable, and it was one of the reasons that people in the South resented the North and so were keen on secession. It's that pride that keeps one from admitting to making mistakes. I think many in the South understood unconsciously that industrialization was the future, not slavery, but they couldn't bring themselves to admit it, and the local slave-holding interests were culturally powerful. It took a long time to break that culture.

I find the Albion's Seed[1] hypothesis to be considerably more convincing for explaining the Southern resentment of the North. The England that colonized the New World was far from a united front. I'm not going to attempt to summarize because it's a complex issue that I won't be able to do justice to in a few sentences. Nevertheless I recommend anyone who is interested to read that book or find a summary from someone more confident of his ability than me. The short version though is that the English immigrants to the new world were neither culturally or even racially[2] homogenous.

[1] https://en.wikipedia.org/wiki/Albion's_Seed

[2] This is why the framers fabricated a notion of "White" identity, to create solidarity where none had really existed. To understand what they meant by race one must look at contemporary dictionaries. Needless to say the word meant something very different over 200 years ago than it does today.

I've not read it. Certainly the colonies were made of different sub-cultures, and that would and did have a major impact in self-identity in the colonies. But even in the South there were large differences from one State to the next, and that leaves slavery- and climate-caused industrialization disparities between North and South as the main drivers of that resentment of the North, and that chip on their shoulder almost certainly exacerbated the South's cultural attachment to slavery. By 1861 the people of the South definitely saw themselves as quite apart from the people of the North, and even quite apart from each other (organizing as a confederacy was not just to be starkly different from the federal North, but also because they had and wanted to maintain very strong national identities in each Southern State).

The Union soldiers were far better fed and equipped than the Confederates.

In the South, which lagged way behind the North for the simple reason that slavery was a disincentive to innovation and industrialization. Alexis de Tocqueville wrote about this. The difference between slave-holding South and mostly-/entirely-slave-free North was stark.

Slavery didn't build the U.S. The mostly-slavery-free North built the U.S.

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The North certainly did trade with the South, and thereby make money. But when the Southern economy was cut off from them, they continued to prosper, which the Southern economy ground to a halt.

The Southerners had expected that they had a trump card with cotton exports to the North, but oops.

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Cotton was also a thread (good joke) attaching the South to the UK, and it was where the resentment of protectionist policies came from. It's all related: slavery, cotton exports, non-industrialization, cultural and economic resentments, dependence on free trade rather than protectionism. It was a very bad mix, so it's no surprise that it ended in war.

The timing was such that it was too late for the South to be able to win independence -- the North was already too strong. But when the North was weaker the drive to secession was also weaker because the resentments were bred in part by the stark contrast in prosperity. The North had to get strong enough to win the war for the South to be willing to go or endure the war.

Sam Houston understood all of this, and for his troubles of advising Texas stay in the Union he was removed as governor by the legislature.