This is a myth. Consider that slavery was introduced before industry was a relevant factor, and large plantations were viable for slavery. Small farmers couldn't afford to keep slaves. In the same way, small artisans and manufacturers rarely had an economic need for (nor the finances to keep) slaves. This is why the north, less suited to large plantations, did not have mass slavery. By the time real factories started popping up, slavery was on its way out throughout the western world, and the north had already parted with it-- for the above reasons, and because of a distinct current of moral outrage. That moral outrage developed before large-scale modern industry, incidentally, and was not a product of it. If that moral outrage had not arisen, and if slavery had stayed, in not widespread, at least fully legal in the north, the emergence of large factories would very likely have been the very thing that could have spread slavery north. A large factory, much like a large plantation, would have economic motives to use slaves. And slaves were in fact used - effectively - in what factories did crop up in the south in the antebellum period.
The idea that industry is the thing that killed slavery is total balderdash. Moral outrage, first conceived on religious grounds and mainly starting in England, is what did slavery in. There was no economic reason to end slavery; Britain profited immensely from it, and still ended it. The Northern USA also profited immensely from it (by taking southern raw agricultural products and turning them into manufactures), but could easily afford to end slavery in its own borders (since it was hardly profitable there, anyway). But do note that the fact that Britain started the notion that slavery was evil (even though it was immensely profitable!) is what swayed many in the northern USA to start seriously opposing slavery, rather than just feeling neutral about it.
I think that preventing the moral opposition to slavery from arising (when it did in OTL) is the key, here. If guys like Wilberforce can be butterflied away, and Britain stays morally okay with slavery for a few decades longer, then the northern USA will stay morally okay with it, too. Still not enthousiastic, but hardly interested in getting rid of it. By the time large-scale industry becomes viable, moral considerations will not have made northern slavery utterly impossible (as they had done in OTl by that point). And then it will soon become evident that the fires of these new industries can very well be stoked by slave labour. That, at least, gives us a set-up for having large-scale slavery in the north exist. Far from industry ending slavery, it could so easily be the thing that makes it a northern institution, as well....
After that, imagine that the later-than-OTL moral outrage against slavery still arises. It's still initially a religious consideration. Suppose that this coincides with boll weevil or something in the south, rendering southern argiculture-based slavery far less valuable. Southern Christians turn against slavery, while formerly wealthy plantation owners, now economically ruined, recoup some losses by selling all their slaves to the northern factories. Two decades later, the South has mostly abolished slavery, while the North is filled with slavery-based factories. As the rest of the world turns against slavery, and the Southern and Western USA try to abolish it as well, the North decides upon a drastic course: secession!