Ha, ha, ha. That's so funny, I forgot to laugh. You are now doubling down on your double-speak. Now you have moved from "the northern States included slavery" to the northern states voted for slavery. Please reread post #61. For your edification, in 1783, Massachusetts Supreme Judicial Court ruled slavery unconstitutional, a decision based on the 1780 Massachusetts constitution. All slaves were immediately freed. I will leave it up to you to figure out how you then overextend yourself to come up with Massachusetts voting for slavery in the Constitution in 1787.
See Article VII. The first sentence reads: “The Ratification of the Conventions of nine States, shall be sufficient for Establishment of this Constitution between the States so ratifying the Same."
All nine northern states voted to ratify the U.S. Constitution which included slavery.
I think if you check the vote roster you will find that Nathaniel Gorham and Rufus King “subscribed” their names as representatives of Massachusetts.