What American dialiect known as Southern Mountain English has been extensively researched by linguist Walt Wolfram?
Walt Wolfram:  He was an active participant in the 1996 debate surrounding the Oakland Ebonics controversy, supporting the legitimacy of African American English as a systematic language system. Appalachian English: Appalachian English, also known in the United States as Southern Mountain English, is American English native to the Appalachian mountain region of the Eastern United States.
Appalachian English