In most cases, historians think, blacks owned slaves benevolently, but exploitative slaveholding by blacks did happen. Some well-off urban blacks owned house slaves, and occasionally craftsmen owned skilled slaves to work under or alongside them. Determining how often this happened isn't easy, since the census didn't consistently distinguish between nominal and actual slaves. Proof of commercial ownership can be found in advertising for runaway slaves, sales of slaves at market rates, etc. A confounding factor is that some free blacks owned slaves both benevolently and commercially. One scholar claims the majority of slave transactions by blacks in Charleston, South Carolina, were commercial but again, South Carolina was unusual, for reasons I'll return to. An analysis of Petersburg, Virginia, suggests only about 10 percent of black slaveholders owned slaves commercially, which was probably typical. Sure, slavery is slavery, but what we're talking about is a far cry from the plantation field slavery you might have imagined.