What's to be upset about? The end had to be in Canada since the Fugitive Slave Act required that runaway slaves be sent back South if apprehended.
They also didn't like the fact that the first slaves sold in the Colonies were in Massachusetts.
If they check their history they would have found that the first slave was in the Virginia/Maryland area.
Nor did they like to remmeber that the triangle trade that made Boston very rich included bringing molasses to Boston to be made into rum which was taken to Africa to be traded for slaves.
Without demand for those slaves the Boston traders wouldn't have brought the slaves anywhere, would they? So the south has no moral high ground in the slave trade scenario.
No, we don't. But the Northern states don't either. Both sets of states had businessmen that grew rich off the slave trade, directly or indirectly.
}:-)4