[citation needed] As a teenager he worked as an assistant to his father and was expected to follow him into teaching; however, he was disillusioned by the insufficiently nationalistic nature of the curriculum and spent a great deal of time writing poetry.
It was at this time, reputedly at the age of fifteen, that he wrote his best-known song, "The Rising of the Moon", which commemorates the Irish Rebellion of 1798.
[1] Following the increasing popularity of his songs and ballads at nationalist gatherings, he moved to Dublin in the 1860s and became active in the Fenian movement.
The further fame engendered by the success of the book led him to be sought after as a speaker; he addressed mass rallies in Dublin, Liverpool and London that year, in the lead up to the Fenian Rising in 1867.
[citation needed] He married Mary Josephine Briscoe in January 1868 and she bore a son Michael, who died shortly after birth in October 1869.