(ETA: Although it’s possible that in the movie adaptation they moved it to the Mississippi Delta.)
Having said that, I’ve never heard that mispronunciation. But I don’t about the locals on Daufuskie during that time frame. Also, the principal called him “Mr. Patroy.” So it wasn’t just the kids. I got the idea from the book that one of the kids called him that, and the name just stuck–but it’s been quite a while.
This is a retelling of The River is Wide, Pat Conroy’s autobiography of teaching kids living on a South Carolina barrier island for one year (Here, he talks about the experience.)
Pat Conroy, an Irish Catholic, Air Force brat (IIRC) from South Carolina, may have worked on his accent since he was in his twenties. Yamacraw Island is isolated enough that even today there is a lot of Elizabethan English in the local dialect. I got the impression that between two heavy accents, the students couldn’t understand his name as he said it. He introduced himself as Conroy and they heard Conrack.
Elizabethan English? Try Gullah. And that’s mostly gone. Daufuskie (called Yamacraw in the book) is a very high-dollar neighborhood now with most of the Conrack-era locals having been squeezed out. The most likely accents you’ll hear are probably New York, New Jersey, Ohio, and Michigan if you go there now.