[4] O'Neill Crowley joined the Irish Republican Brotherhood and led a local group in Ballymacoda of about 100 men.
Under the command of Captain John McClure, he was part of the 5 March attack on Killadoon coastguard station, with the aim of seizing weapons kept there.
However, there were only a few men to meet them; the rising was a failure in the area, in part due to snowy weather and local informers.
[5][7][better source needed] Many places in County Cork are named for O'Neill Crowley, including: In 1898 a monument to his memory was erected at Sraharla, on the road to Kilfinane, near to Kilclooney Wood.
[14] An Irish rebel song in his honour is recorded: As I rambled out one evening, all in the month of June, I strayed into an old churchyard to view a noble tomb.
It grieves my heart to see you there, a hero once in bloom, But untimely death has brought you here to fill a silent tomb.
It’s many the mile we shouldered you, a storín gheal mo chroí, [Irish: "bright darling of my heart"] Because you were a Fenian boy and died for liberty.