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.
William LabovWe focus upon pairs of words very often which are the same in some areas and different in other areas.
William LabovAn important aspect of the current situation is the strong social reaction against suggestions that the home language of African American children be used in the first steps of learning to read and write.
William LabovBut unlike European countries, America has never finished a map of the United States, only the eastern United States is covered and a few spots here and there.
William Labov