The North literally committed treason by illegally denying the South the right to leave (10th Amendment) and then levying war against them (the very definition of treason in the US Constitution).I wasn't completely sure on the context of this question, but I think you're asking me to show you someone who deserves the credit for ending slavery in the USA more than Lincoln does?
I don't think there is one; that's the point. As much as a single person could ever take credit for such a thing, I think the credit rightly goes to Lincoln.
All because they couldn't let their tax base that was financing the corrupt industrialists in the North get away.
There is no possible argument to be made for saying Lincoln was a good person in 1861 unless you say Washington was a bad person in 1776.