A worker in the Bank of America Corporate Center in Charlotte who asks you to “mash the button” for the elevator or to “he’p him tote the computer right yonder” would get a quizzical look or a patronizing chuckle for “talking country” in the towering edifice representing the second-largest financial center in the United States. But those who react in condescension may not realize that this way of speaking was the dialect norm in the city just a couple of generations ago—and probably in the residential home that once stood on this site. As one...