Bill, I quantified exactly how much or how little BOTH white slaveholders and black slaveholders were complicit in slavery. It can be extrapolated from the 1830 Census, which was the basis of the article by Henry Louis Gates, quoting from G. Cater Woodson, that you linked to.

Black slaveholders, according to the census, owned fewer than  0.6% (I rounded up) of the 2.1 million slaves counted by the 1830 Census. Given that a couple of the "civilized tribes" owned about 10,000 slaves at various times I'm willing to  allow that 1% of the slave population was, conceivably, owned by then-despised groups, indigenous men and free men of color.

This means that 99% of American slaves counted in 1830 belonged to white folks. 

If you render these percentage in ratio, 99/1 and then convert the ratio itself back to percentages, the amount of white-owned slaves exceeded black-owned slaves by close to 9900% (since 100% of 1 =1). That's exactly how much or little each group was morally culpable.