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.
“European citizens expect that there will be also a fair system inside the European Union and in the euro, and that's why we have to have quite hard discipline.”
“Mr. Speaker, less than 10 percent of our Nation's children walk or ride their bicycles to school, and too many schools continue to invite fast-food vendors into their cafeterias.”