O'Mahony, who was a Gaelic scholar, named his organisation after the Fianna, the legendary band of Irish warriors led by Fionn mac Cumhaill.

[3] The Fenian Brotherhood trace their origins back to 1790s, in the rebellion, seeking an end to British rule in Ireland initially for self-government and then the establishment of an Irish Republic.

Following the collapse of the rebellion, the British Prime Minister William Pitt introduced a bill to abolish the Irish parliament and manufactured a Union between Ireland and Britain.

[citation needed] In the early 1840s, the younger members of the repeal movement became impatient with O'Connell's over-cautious policies and began to question his intentions.

[citation needed] The revolt's failure was much influenced by the general weakening of the Irish population after three years of famine, mixed with premature promptings to rise up early, resulting in inadequate military preparations in turn contributing to disunity among the rebellion's leaders.

[7] John Mitchel, the most committed advocate of revolution, had been arrested early in 1848 and transported to Australia on the expressly created charge of Treason-felony[citation needed].

He was to be joined by other leaders, such as William Smith O'Brien and Thomas Francis Meagher who had both been arrested after Ballingary escaped to France, as did three of the younger members, James Stephens, John O'Mahony and Michael Doheny.

Both Fenian factions raised money by the issue of bonds in the name of the "Irish Republic", which were bought by the faithful in the expectation of their being honoured when Ireland should be "A Nation Once Again".

Large quantities of arms were purchased, and preparations were openly made by the Roberts faction for a coordinated series of raids into Canada, which the United States government took no major steps to prevent.

[citation needed] Many in the US administration were not indisposed to the movement because of Britain's actions of what was construed as assisting the Confederacy during the American Civil War, such as CSS Alabama and blockade runners smuggling in weapons.

[citation needed] Roberts' "Secretary for War" was General T. W. Sweeny, who was struck off the American army list from January 1866 to November 1866 to allow him to organise the raids.

[citation needed] In April 1866, under the command of John O'Mahony, a band of more than 700 members of the Fenian Brotherhood arrived at the Maine shore opposite Campobello Island with the intention of seizing it from the British.

[citation needed] Le Caron later asserted that he distributed fifteen thousand stands of arms and almost three million rounds of ammunition in the care of the many trusted men stationed between Ogdensburg, New York and St. Albans, Vermont, in preparation for the intended raid.

[citation needed] The raiding party crossed the border into Manitoba at Pembina, Dakota Territory and took possession of the Hudson's Bay Company trading post on the Canada side.

U.S. soldiers from the fort at Pembina, with permission of Canadian official Gilbert McMicken, crossed into Canada and arrested the Fenian raiders without resistance.

At the inauguration of the mainline of the Canadian Pacific Railway in 1885, photos taken of the occasion show three large British warships sitting in the harbour just off the railhead and its docks.

[15] After the 1867 rising, IRB headquarters in Manchester opted to support neither of the dueling American factions, promoting instead a new organisation in America, Clan na Gael.