Here's where their methodology breaks down. When you look at culinary records from Northern sources, you find severe discrepancies between type and numerical combination of ingredients between any two foods of the same name, which make Southern recollection highly suspect. And even if you take Southern records at face value, the records show so much variation across the states that you really cannot claim there is any such thing as a "Southern food" much less a "Southern culinary tradition."
In addition, economic disparities precluded African American cooks from gaining access to the same quality ingredients as their white counterparts, so it is a myth that white and black cooks could have similar sentiments towards their cooking or those that who were eating it.
A little levity, gentlemen.
Truth be told, I am intrigued by this class and have read their online interviews. Fascinating stuff. It makes me miss my grandmother- may her memory be eternal. Oh, the culinary magic she conjured!