Whist I know that schoolteacher Thomas Hodge, who emigrated from Ballyroan to Waterbury, Connecticut, is said to have brought the song with him in the 1870s, there is a problem in that that there was no Scully’s pub in Ballyroan at that time. In the census returns of 1901 and 1911, the family were recorded as agricultural labourers. Scully’s pub was certainly established by the 1950s and possibly some decades before that.
However, the tradition I have is that Christopher O'Byrne (1863–1950) of Ballyglishen, Abbeyleix wrote Skies O’er Ballyroan for a friend of his who lived in Ballyroan. This was the story as I was told by his nephew and niece, Daniel and Josephine Gleeson.
I am not saying that this is correct, but in view of the comparatively recent age of Scully’s pub, I think that some more research needs to be done.