They came from Negro's who kidnapped them from African and sold them to the elitists in the northeast.
You know, one get the idea that the primitives think the Portuguese, Spaniards, English, and all that, invaded the continent of Africa and carried away the natives to become slaves in the New World.
Yeah, right.
The Europeans didn't dare go inside Africa; it was all too strange and mysterious and killing (i.e., diseases) to them.
It was just easier to pull the ship up to some cove or bay, and barter with the nearby African chieftains for slaves, who were other Africans captured by.....Africans.
Some Africans became mighty wealthy in the slave trade.