The prevailing wisdom, since I was a child, was that during slavery, the enslaved found freedom in the North. So, that led to the false belief that the North was a safe haven for escaped slaves.

As I have grown older and studied, I have learned that slaves were treated as less than in the North. And this exact point that you touched on about NEw York City being deeply entreneched in the cotton inudstry, and the potential for succession... I learned this a week ago. Every time a falsehood from my childhood education is dispelled, I am grateful, but it also stings a little, because predominantly, the new information I learn is never positive.