In jeffersondem's defense - and I still cannot believe I'm saying that - if we trace the creation of the original 13 states to the Continental Congress and the Declaration of Independence then strictly speaking all of them abolished slavery after they became states. On the other hand, if we trace states back to the ratification of the Constitution then you are correct and five Northern states and Vermont had abolished slavery before then.
I too am surprised that you are defending him. Maybe it’s because he said he likes you. You know that he now wants to reply with, “critic answers critic”. He has become predictable and needs fresh material. Please note again the wiki entry. Vermont was slave free when it became a state in the United States. Just prior, it was independent (not yet a part of the U.S.) and slave free. I will stand by my statement that at no time in the history of the United States can it be truly said that “all the northern states were slave states (”original” or whatever). I guess it depends on his clever cover-up of “original states” and whatever that is intended to mean in his mind.