[To set the stage, here's a brief quote from Wikipedia as regards the 'Wild Geese,' cited in this song:
'The Flight of the Wild Geese was the departure of an Irish Jacobite army under the command of Patrick Sarsfield from Ireland to France, as agreed in the Treaty of Limerick on 3 October 1691, following the end of the Williamite War in Ireland. More broadly, the term Wild Geese is used in Irish history to refer to Irish soldiers who left to serve in continental European armies in the 16th, 17th and 18th centuries.']
My comment: In this song the term may be more loosely used to mean rebels or runners of contraband, but I can't be sure just how it is meant.
Now to my main point: I'd be interested to know more about the history of this magnificent song. I learned 'Sailing in the Lowlands Low' in 1958 from an older friend, Bob Keppel of St. Louis. He had learned it from a 78 rpm record (probably issued c. 1940s) sung by Christopher Casson on Copley, one of the Irish/Irish-American record labels then current around Boston. I know of no earlier recorded source. Tommy Makem later recorded it with the Clancys.
Since Patrick Joseph McCall lived 1861-1919 (see Wikipedia), the text was written in the late 19th or early twentieth century. The tune appears without text or comment in Joyce's Old Irish Music and Song, 1965 ed., and thus presumably in the 1909 first edition, which I haven't seen. I don't know whether text and tune were both McCall's, or whether they were joined later.
Given its beauty and creativeness, it's odd that 'Sailing in the Lowlands Low' (or as 'Lowlands Low,' but not the sea chantey of that name) does not appear in Sam Henry, Patrick Galvin's Irish Songs of Resistance, Clancy Bros. songbook, Zimmerman's Songs of Irish Rebellion, not even in 'Twas Only an Irishman's Dream,' or any other printed Irish song source I have found.
That's as much as I've been able to learn. The song is among my favorites, and I still sing it.