Java Joe’s Gourmet Corner is one of a new breed of sandwich shops opening around the city. Once Baltimoreans were content with corned beef on rye and a Coke for lunch; then they discovered cappuccino.

Atlanta is living in a golden age of chicken sandwiches. Few of them are as biographical as Alvin Sun’s ABC fried chicken sandwich, which stands for “American-born Chinese,” and tells his life story ...