The Johnstons were an Irish folk band from Slane in County Meath. This song is about a soldier based in the Curragh, in County Kildare, the main military base for colonial troops stationed in Ireland. It is typical of many songs written in Ireland that were associated, in some way, with the British military presence there. Not all of those songs were overly critical of the foreign presence. Whiskey in the Jar is another.
The version of The Curragh of Kildare most commonly heard today was adapted by the Scottish poet, Robbie Burns, who is said to have taken it from an earlier ballad titled The Lovesick Maid. In that version, the lyrics referred to a highwayman named Johnson (certain poetry there perhaps?) who was hanged for his deeds. Some versions have the narrator as a male and some as a female. The modern version would seem to cast a woman in the lead role. She pines for her man who is in Kildare, presumably about to be executed.
Ireland has been the victim of colonialism for 800 years, and that continues today. It’s understandable if unfortunate, perhaps, that so many beautiful ballads contained stories that revolved around the occupying forces and their steely grip upon the land and the indigenous people. It will be wonderful when the last of those colonial troops leave Ireland and the country is again free and at peace, instead of in two pieces.