The first slaveholder in the US was a black man. Where do you think slaves were bought from? From blacks selling other blacks.
So what? Are you saying that justifies it? Who ever "started it", it was still immoral.
And I have no doubt that there was a black man in NC who owned a large number of slaves and used them for slave labor. Again, so what?
Your point, I think, was that blacks were just as guilty as whites for slavery. That is not supported by the facts. In the 1800s a white minority kept a black majority in slavery.