The reason that states existed at all in the north - despite states having laws forbidding it - was because of the supreme court.
Even Abraham Lincoln had declared himself as a non-abolitionist until the Gettysburg Address. He campaigned, and started his governing as a status-quo politician. The main thing that southern politicians railed against him was that he wanted to keep the compromise and have the "new territories" (areas that were not yet states) be kept non-slave territories.
There is nuance here, but basically the Confederacy pissed him off so much that he changed his mind and decided that he would push for the abolition of slavery, starting by ending it by force in the Confederacy. He moderated after the war somewhat, and his death (at the hands of a Southern conspiracy to re-start the war and bring back slavery) almost got us to full equality, but wound up in a compromise that got us the Jim Crow laws.
I had always believed that Kentucky was neutral in the Civil War. Both Lincoln and Jefferson Davis (President of the Confederate States) were born in Kentucky.
Reading the wikipedia article[0], it seems like it's really complicated but it still looks mostly correct to me that Kentucky was more neutral than not.
[0](https://en.wikipedia.org/wiki/Kentucky_in_the_American_Civil...)
No, it wasn’t. “States rights” is a later pro-slavery slogan. It is not and never has been the same thing as loose federalism.
And there were, in fact, slaves in the North until it was abolished nationally (in more states at the time of the Revolution than at the time of the Civil War, and even fewer at the end of the Civil War, but the last three states where slavery existed until terminated by the 13th Amendment were Kentucky, Delaware, and New Jersey.)