Huh?? I have yet to hear blacks speaking Swahili or insisting on bilingual ed --- they all speak English --- even immigrant blacks seem to pretty much all speak English. As far as blacks assimilating --- they pretty much invent much of our cultural fads --- the clothes the hairstyles, the music. Elvis and many others imitated black musicians. You saw white people wearing afros and corn rows --- and the baggy pants --- the rap music --- blacks started all that --- it's more like everyone else assimilates into what they start.
Black immigrants speak english better than most inner city blacks. They are also better educated and very conservative. The US inner city black culture needs to be destroyed.