The dual parent family only started to break down when the government launched its "War on Poverty" which provided incentives against dual-parent households. Only then did the AA community go down to 25% in-wedlock births.
It is also happening to whites, but to a lesser degree. I assume that is not because of skin color (which I consider to be irrelevant) but rather to differences between lifestyles and government services in urban vs. rural areas.