Currently in these United States of America, there is murmuring about potential civil war and a 150 year review of the last civil war. The Civil War was caused by the institution of slavery, tariffs, states' rights, etc. (pick a link). It might have also been a violent flare up in the Puritan-Cavalier struggle in post-Reformation English history that continues today. Economic causes are given a little attention. There's focus on tariffs, taxation, and if you have a good college professor, they may bring up the issue of the South being a source of government revenue for infrastructure expenditures primarily in the north and midwest. The south was a commodity based export economy with less of an attachment to the American System, but their tax dollars came in handy. Why didn't the North just let the south go and later use British help to get them to end slavery? Why didn't the North just buy the slaves out as had been proposed at times? Ron Paul agrees but Gateway Pundit says no. Paul is right that it could have happened, but there is no way it ever would have happened because of the transition in American capital that would have occurred.
The north had taken in plenty of immigrants to boost its numerical superiority in the House of representatives (which controls domestic spending) to the point where it sucked money out of the south to redistribute where it pleased. Expanding the franchise meant there were more votes to buy even in our rudimentary republic than the founders' envisioned. The federal government could have bought the slaves for anywhere from $400 mil to $2.7 billion. Cheaper than the Civil War's cost of $6.6 billion, but it's not that easy since the government doesn't create wealth. The cost would have been a government transfer of wealth within the nation of whatever price tag agreed upon by the government and slave owning interests from revenue generators in the rest of the nation to southern elites. About 80% of southern whites did not own any slaves, so this would have been an elite to elite or at least northern revenue generators to slave holders (commodity sources) transfer.
That money would have become political power as well as economic power. The southern interests could have bought whatever they wished for a political scene or even guided America to be a commodity powerhouse, which coal, oil and western resources would have fueled. What would all of those former slave owners have done with their newfound cash capital? The southern elites could have invested where they saw fit. They could have taken advantage of newly freed slaves who had no expectation of living standards besides their slave past and created a facsimile of the factory system down south. The freed slaves would have driven down the price of labor, making southern labor price competitive with the north. Northern business interests would have been under pressure.
The north isn't going to buy them back. They don't even keep that hope alive going even after Antietam. The north proceeds to remove the slaves without compensation and then destroy the south lock stock and barrel. Antebellum America shows a south with a higher estate value per head of $3978 vs. the north at $2040 in 1860. The south had a worse distribution of wealth due to it's capital solely being land and slaves. There was little to no banking system in the south. The south had land and slaves. The infrastructure was far less developed, the economy was not multidimensional, and even their ports were in poor condition and few were deep water compared to the north. Half of the south's regional value was in slaves. Deciding to not buy off the slaves was similar to robbing the south of it's major source of capital. Wage a war that destroys the limited railroads, a lot of farmland, cities, and what the hell is left? Not to minimize the human cost of war, because they lost so many of their young men, but I'm focusing on investment capital and wealth. Destroying the south and ending slavery without compensation set the southern banking and economy back decades. They lost their asset for trading and collateral in any investment. They couldn't rebuild. Reconstruction itself benefitted many northerners (carpetbaggers) and removed an entire block of elites from reaping the rewards of the post-Civil War economic boom.
The Civil War destroyed an economic power base, which in a democracy means a political power base. The south's elites still reaped rewards after the Civil War, but not like northern elites. The Civil War could have been avoided with a financial transaction. With enough persuasion, the southern elite could have been cajoled and molded into creating a system down south that the north would employ on all those immigrants streaming off transatlantic ships. The elites play a game with us, and only occasionally do we get a chance to set them back a bit. I do think the north could have avoided war. They just did not want to pay those dastardly slave holders. That religious root of abolitionists would not buy their goal. The north wanted them dealt with, marginalized and removed from the coming great growth that was the Gilded Age.