Again, I do not prescribe to a generic and over-arching/blanket statement. African American men I, or my husband, have met just do not place such a heavy emphasis on the fact that they are African American as cucks. It seems most only care about their ethnicities when they are speaking about them in terms of being "bulls" or whatever.
Anyway, how did hubby start in the lifestyle? We did it together, just like we did with everything else regarding our relationship. We're boring, we don't have one of those porn stories for how we started. We found cuckolding as a couple, browsing the internet together and we were already poly. No emphasis was placed on race/ethnicity of people I would be with and we just wanted to see each other happy. I know, boring but it is what it is.