Fenians Plot to Hold Canada Hostage

For centuries Britain had been obliged to commit enormous resources to control Ireland and suppress rebellion there. But in the wake of colonial expansion, the Crimean War, the Great Mutiny in India, and rising tensions in Europe, these resources were being strained by the 1860s. One of Britain's early responses was to pare down its military commitments in British North America and attempt to turn over the responsibility of defence to the colonies themselves. Anything the Fenians could now do to keep the British busy in Canada would drain the resources and political will available for Ireland, or so the Fenians thought.

--Peter Vronsky, Ridgeway: The American Fenian Invasion and the 1866 Battle That Made Canada, The History of Canada Series (Toronto: Penguin Group, 2012), 11.