A big reason why slavery was abolished in so many countries was the defeat of the Confederacy. It signalled that slavery was definitely on its way out. Spain and Brazil probably would have kept slavery longer if the Confederacy had been successful, and a powerful country run by the "slave power" would be a focus for efforts to spread the institution.
Would we have slavery in North America today without Lincoln? Probably not, it would have been abolished at some point. Though "at some point" might mean well into the 20th century. And even then, abolition might have been purely formal. Does that mean that abolition in 1865 rather than in 1880 or 1900 or 1920 justified the great losses of war? The thing is that you don't see those losses in advance. Had people known that war would take hundreds of thousands of lives, they might well have done things differently, but unionists acted according to the best knowledge that they had at the time.
But that line of arguing's a little insulting. Nazism didn't last in Poland. Nor did Communism. But ought the Poles simply have sat back, folded their hands, and done nothing confident that eventually history or economics would set everything to rights and vanquish the inefficient system? I don't argue that the two cases are exactly the same, but there are similarities. Nowadays, some people assume that left alone, conditions would inevitably have advanced by themselves to what we have now without anyone taking action, and that's just not true.
But if done peacefully, gradually and by consensus it would lead to the enfranchisement of blacks and granting them the same land and resources for startup as white settlers were getting.
That's wishful thinking. Confederates probably would have gotten rid of slavery at some point, but they wouldn't have set up Blacks as equals or given them a share of their own resources.
In addition the original sovereignty of the sates would be preserved and federal government would not become the main dominating center of American political life.
Again, that's wishful thinking. I'm not sure just how "sovereign" the states were in 1840 or 1850 or just how much was really changed in federal-state relations by the Civil War. But the idea that without the Civil War history would just have stopped at 1860 without further changes, looks naive. So does the notion that a real system of "sovereign states" would be better than a more federal system. Government could have grown much as it did over the last two and a half centuries. Or the country could have fallen apart completely into warring states.
"State sovereignty" looks a lot like a recipe for chaos, like Africa today or Poland under the liberum veto. I don't say Lincoln was our best President, just that the arguments of those who think him the worst don't hold up very well.
Not true my dear. The slavery in other countries was abolished BEFORE the Civil War. Even serfdom in Russia was abolished just as Civil War started (serfdom in Russia was the last remaining in Europe). And slavery was eradicated much earlier than serfdom!
No, bloody Civil War was very bad and the following abandonment of American blacks who did not get any help to stand on their feet not any better.
The main thing Lincoln achieved was the destruction of the sovereignty of states and creating powerful central government.
Nobody attacked Nazism. It was Nazism which attacked others, overextended itself and was crushed by the Soviet Communists (with the help of USA and England). Communism was not overthrown by force, it was the "history or economics" which "set everything to rights and vanquish[ed] the inefficient system" from inside. We must live on parallel universes, Sir.