It is entirely possible that both the North and the South would be much better off if the war of 1861-65 had not been pursued. Few historians even mention, much less really examine, the cost in human lives that war cost both sides. And that leaves out the total costs of the almost total destruction of the South's economy, a destruction that took at least 100 years for the South to recover.
For sure the South would have been a far stronger nation, and that would have been soon free of slavery too. Slaves in large numbers were needed because of the labor intensive operations of large plantations, the source of income for that agreculteral South. Slaves were expensive to own and maintain, a barely cost effective work force at best but there simply were no excess "laborers" in the South to be hired at the pay the land owners could afford to pay. But, when effective farm machinery from the Industrial Revolution became available the need, and therefore the use, of slaves would have rapidly vanished. Then slaves would have been freed by economic neccessity. Freed slaves would then not have been cast aside as worthless humanity in a destroyed region, as was the case at the end of the great conflict. Thus, the slaves themselves would have benefited greatly by a staged freedom into a sound economy that could have absorbed them.
For whatever reason, the thrist for personal freedom that was first seen in Mass. has long vanished from the northeast. Northerners of today seek cradle to grave security and physical comfort and are willing to surrrender great chunks of personal freedom to attain it.
Witness, the North is the strong hold of group-think political liberalism. They show a desire for massive government regulation and control of personal actions, like gun control and control of private property, They support ever increasing governmental services to reduce the need for personal responsiblity. They have been shown themselves to be willing to pay high taxes for the subjugation big government brings. The Northern economy has long been the home of large corporations, large unions and eletist, powerful political families. They oppose "right to work" laws for the protection of big unions. They have a minimal concern for small businesses and personal responsibility. They support large government payouts for charitable causes but have the lowest percentage of such personal contributions in the nation. They vote for the greatest amount of personal property restrictions by city zoning laws and home-owner associations. Etc.
Southerners have, at last, developed a diverse industrial base that is strong an growing while many of those in the North are closed or declining. This has led many Northerners to migrate to the South in the recent past. Here, they seem determined to force on us the blessings they used to destroy the quality of life their home states. In much of the South northern accents now greatly outnumber southern drawls. Previous generations of southern politicians have been replaced with liberal minded northern types, so expanding taxes and regulation and failing schools - all for the good of the people of course - are growing here by leaps and bounds.
So, for sure, at least the South would be much better off without the damage of that war. And if we were allowed to regulate our borders today the invaders from both north and south could be limited. But, as everyone who has met a loud-mouthed liberal northerner (is that a redundant term?) can confirm, masses of Yankees can't be controlled and they also forbid us to seriously work to control our borders further south.
Such is war. In my humble opinion.