If you mean utilizing them agriculturally, then you are correct. The sordid truth is that the North, lead by New England, didn't really become 'abolitionist' until the British Navy effectively closed down the trans-Atlantic slave trade. That trade was quite lucrative for coastal New Englanders, and they didn't develop a distaste for the institution, until they could no longer profit from it...
the infowarrior
I think that is unfair. The famous family of Captain Brown family made much money, and then had a severe family squabble over slavery. A grandson of Captain Brown won fame with his effective defense of free soil communities in Kansas (after his son wrote him about proslavery raids), and was later executed by Virgina for treason, though he had never sworn allegiance to that state.
> “If you mean utilizing them agriculturally...”
Yes, when I said “Slavery had never been profitable in the more northern part of the country”, I was thinking of slaves actually working within the states. I didn’t consider New England’s earlier involvement in the transatlantic slave trade.