I agree with a fast Civil War meaning no large scale emancipation. Northern politicians after a certain point in history were almost entirely anti-slavery, either out of idealistic abolitionist concerns or just because it made no sense to their constituents or the North (which had moved away from any sort of economy that would benefit from large scale slave holding.)
The reason the North had quite simply kow towed to Southern desires for a generation is because of a genuine fear of the Southern states leaving and a war. The North feared how bad the war could be and how disastrous for the country secession would be. They feared how losing the Southern states would affect all manner of things, from Westward expansion to international relations especially with European powers.
Once the war started, there was a window at the beginning. If the South had capitulated quickly, the North would probably revert to the status quo ante, and be happy that the ugly incident was over. Once the cataclysm was well under way, enough people in the North had become committed to the grim affair that the thought became “well, the worst has happened, no fucking reason to pander to the South at all now–they are officially doing the absolute worst they can do and it can’t get any worse.” Once it became obvious a few hundred thousand men and billions of dollars ($6bn in 1860s dollars, a huge number adjusted to 2011 dollars.) had to be spent to end the thing, there was really no reason to end it on terms with any consideration to the South at all.
The only real bargaining chip the South ever had was that it could end it quick and let everyone up North go home and get back on with their lives. If they had played that chip quickly they very well may have been able to maintain slavery for another generation. Once enough blood and wealth had been lost, the North had no reason to give a shit how the South felt about emancipation.
The border states were also a big issue that a few years in were much less of one, and are worth noting (the Civil War could have been different if Kentucky, Missouri, and Maryland had seceded.)