It appears that the present-day form of African American English is not the inheritance of the period of slavery, but the creation of the second half of the 20th century.
“I do not want to go into its physical reasons: the construction of the human body is different from that of carnivorous animals. But man's intelligence is such that it can be utilised to defend any-thing he does, whether right or wrong.”
“But I dare not think too far into the future on the risk that I'll miss the present.”