What significance is there to Irish heritage in Margaret Mitchell's Gone with the Wind?
True. And that is ironic considering that, upon visiting the Margaret Mitchell home in Atlanta (the museum), the first thing that comes in the tour are all the Irish superstitions that the family abided by, and the Irishness is quite a strong element in the everyday life of the author. It is most interesting. Would be great if you could visit it, though it is not as historical as you would think, but the diaries of the family are there.
Have you read the so-called sequel, Scarlett, by Alexandra Ripley? The O'Haras' Irish heritage plays a huge role in that novel.