Yes there were. What’s your point? The fact is that each of the northern states had a plan or timeline for the eventual abolishment of the practice. It is noteworthy to mention that zero of the southern states had similar plans - or even an incentive to discuss such plans.
I agree there were movements to keep the new states and territories slavery free.
Slavery would have ended in some states of its own weight. Crop changes such as those happening in Maryland from tobacco (still labor intensive) to produce farming (not so much) to support growing cities like Baltimore and Washington, D.C. had led to increased manumission.
The trend was also becoming established that laborers were cheaper to hire, required little to no initial investment (which would be forfeit in the event of misfortune), and could be replaced readily. What's more, you paid them, they found their own housing, food, and clothing, and medical care, unlike a slave where failure to provide all that would lead to less than optimal returns on (or a loss of) the owner's investment.
I'm not even being an apologist for slavery--I find the institution deplorable. I'm just saying that until mechanization came along to harvest labor intensive crops, slaves or field workers (illegal immigrants?) were part of the mix.
The whole illegal immigrant farm worker thing was started by that.
Sure people will say "greed", but when what you get for a crop won't support the farm and higher wages, you cut costs.