Overview
John Kearney was a member of Clann na Gael and captured during what was called the Fenian dynamite campaign (1881 to 1885).
Background
After the failure of the rebellion of 1867 and of the raids on Canada in 1866 and 1870, many American Fenians were disillusioned about any campaign to counter the British presence in Ireland.
However, Alfred Nobel's 1866 invention of Dynamite, appeared to some members as the remedy for the ailing 'physical-force' movement. With combined with the new innovation of clockwork timers, members of the Irish Republican Brotherhood (IRB), and Clann na Gael started the Fenian dynamite campaign (1881–85), which sustained a campaign incorporating a series of explosions in British urban centres.
Through the use of explosives and timers (modern technology at the time), the Irish question affected daily life in British cities for the first time.
From Wikipedia (CC BY-SA 4.0).