John T. Edge, director of the Southern Foodways Alliance, at his office at the University of Mississippi in Oxford, Miss., May 4, 2017. In his new book "The Potlikker Papers: A Food History of the Modern South," Edge writes of his struggle to reconcile his "profound love of the South with the deep anger that boiled in me when I confronted our peculiar history." (Andrea Morales/The New York Times)