It make sense that New York would be one of top slave cities.
Originally, it was called New Amsterdam.
The Dutch Jews organized and ran the slave trade in the North and South Americas from there.
It makes sense because NYC was the center for trade on the East Coast and slaves were an important commodity. Slaves weren't just used in the southern cotton flelds, Yankees used them in all kinds of ways up to the begining of the industrial revolution. If you want to make a religious issue out of it you could investigate the muslem slave trade that existed then and still exists.
Not trying to make it a religious issue at all.
You mentioned that New York City was number two in the amount of slaves.
I was just pointing out that it was the epicenter of the American slave trade and ran by the Dutch Jews who lived there.