Fenian raids Between 1866 and 1870 , the Fenian raids of the Fenian Brotherhood , who were based in the United States , on British army forts , customs posts and other targets in Canada , were fought to bring pressure on Britain to withdraw from Ireland . They divided Catholic Irish - Canadian s , many of whom were torn between loyalty to their new home and sympathy for the aims of the Fenian s . The Protestants from Ulster were generally loyal to Britain and fought with the Orange Order against the Fenians . While the U . S . authorities arrested the men and confiscated their arms , there is speculation that some in the U . S . government had turned a blind eye to the preparations for the invasion , angered at actions that could have been construed as British assistance to the Confederacy during the American Civil War . There were five Fenian raids of note . Campobello Island Raid ( 1866 ) . Led by John O ' Mahony , this Fenian raid occurred in April 1866 , at Campobello Island , New Brunswick . A Fenian Brotherhood war party of over 700 members arrived at the Maine shore opposite the island intending to seize Campobello from the British . British commander Charles Hastings Doyle , stationed at Halifax , Nova Scotia responded decisively . On 17 April 1866 he left Halifax with Royal Navy warships carrying over 700 British regulars and proceeded to Passamaquoddy Bay , where the Fenian force was concentrated . This show of British might discouraged the Fenians , and they dispersed . The invasion reinforced the idea of protection for New Brunswick by joining with the British North American colonies of Nova Scotia , and the United Province of Canada , formerly Upper Canada ( now Ontario ) and Lower Canada ( Quebec ) , to form the Dominion of Canada . Niagara Raid ( Battles of Ridgeway and Fort Erie ) ( 1866 ) . The Fenians now split into two factions . The original faction led by Fenian founders James Stephens and John O ' Mahony focused more on fundraising for rebels in Ireland . The more militant " senate faction " led by William R . Roberts believed that even a marginally successful invasion of the Province of Canada or other parts of British North America would provide them with leverage in their efforts . After the failure of the April attempt to raid New Brunswick , which had been blessed by O ' Mahony , the senate faction implemented their own plan for invading Canada . Drafted by the senate " Secretary for War " General T . W . Sweeny , a distinguished former Union Army officer , the plan called for multiple invasions at points in Canada West ( now southern Ontario ) and Canada East ( now southern Quebec ) intended to cut Canada West off from Canada East and possible British reinforcements from there . Key to the plan was a diversionary attack at Fort Erie from Buffalo , New York , meant to draw troops away from Toronto in a feigned strike at the nearby Welland Canal system . This would be the only Fenian attack , other than the Quebec raid several days later , that would be launched in June 1866 . Approximately 1000 to 1 , 300 Fenians crossed the Niagara River in the first 14 hours of June 1 under Colonel John O ' Neill . Sabotaged by Fenians in its crew , the U . S . Navy ' s side - wheel gunboat did not begin intercepting Fenian reinforcements until 2 : 15 p . m . — fourteen hours after Owen Starr ' s advance party had crossed the river ahead of O ' Neill ' s main force . Once the USS " Michigan " was deployed , O ' Neill ' s force in the Niagara Region was cut off from further supplies and reinforcements . After assembling with other units from the province and travelling all night , the Canadians advanced into a well - laid ambush ( Battle of Ridgeway ) by approximately 600 - 700 Fenians the next morning north of Ridgeway , a small hamlet west of Fort Erie . ( The Fenian strength at Ridgeway had been reduced by desertions and deployments of Fenians in other locations in the area overnight . ) The Canadian militia consisted of inexperienced volunteers with no more than basic drill training but armed with Enfield rifled muskets equal to the armaments of the Fenians . A single company of the Queen ' s Own Rifles of Toronto had been armed the day before on their ferry crossing from Toronto with state - of - the - art 7 - shot Spencer repeating rifle s , but had not had an opportunity to practise with them and were issued with only 28 rounds per man . The Fenians were mostly battle - hardened American Civil War veterans , armed with weapons procured from leftover war supplies , either Enfield rifled muskets or the comparable Springfield . The opposing forces exchanged volleys for about two hours , before a series of command errors threw the Canadians into confusion . The Fenians took advantage of it by launching a bayonet charge that broke the inexperienced Canadian ranks . Seven Canadians were killed on the battlefield , two died shortly afterwards from wounds , and four would later die of wounds or disease while on service ; ninety - four more were wounded or disabled by disease . Eight Fenians were killed and sixteen wounded . After the battle , the Canadians retreated to Port Colborne , at the Lake Erie end of the Welland Canal . The Fenians rested briefly at Ridgeway , before returning to Fort Erie . Another encountered followed that saw several Canadians severely wounded and the surrender of a large group of local Canadian militia who had moved into the Fenian rear . After considering the inability of reinforcements to cross the river and the approach of large numbers of both militia and British regulars , the remaining Fenians released the Canadian prisoners and returned to Buffalo early in the morning of June 3 . They were intercepted by the gunboat " Michigan " and surrendered to the American navy . Until recently it was alleged that the turning point in the battle was when Fenian cavalry was erroneously reported and the Canadian militia ordered to form square , the standard tactic for infantry to repel cavalry . When the mistake was recognized , an attempt was made to reform in column ; being too close to the Fenian lines , it failed . In his recent new history of Ridgeway , however , historian Peter Vronsky argues the explanation was not as simple as that . Prior to the formation of the square , confusion had already broken out when a unit of the Queen ' s Own Rifles mistook three arriving companies of redcoat Hamilton 13th Battalion for British troops . When the Queen ' s Own Rifles began retiring to give the field to what they thought were British units , the 13th Battalion mistook this for a retreat , and began withdrawing themselves . At this moment that the infamous " form square " order was given , completing the debacle that was unfolding on the field . A board of inquiry determined that allegations over the alleged misconduct of Lieutenant - Colonel Alfred Booker ( 13th Battalion ) , on whom command of Canadian volunteers had devolved , had " not the slightest foundation for the unfavourable imputations cast upon him in the public prints " . Nevertheless , the charges dogged Booker for the rest of his life . A second board of inquiry into the battle at Fort Erie exonerated Lieutenant - Colonel J . Stoughton Dennis , Brigade Major of the Fifth Military District , although the President of the Board of Inquiry , Colonel George T . Denison , differed from his colleagues on several key points . Five days after the start of the invasion , U . S . President Andrew Johnson issued a proclamation requiring enforcement of the neutrality laws , guaranteeing the Fenian invasion could not continue . Generals Ulysses S . Grant and General George Meade went to Buffalo , New York to inspect the situation . Following instructions from Grant , Meade issued strict orders to prevent anyone from violating the border . Grant then proceeded to St . Louis . Meade , finding that the battles were over and the Fenian army interned in Buffalo , went to Ogdensburg , New York , to oversee the situation in the St . Lawrence River area . The U . S . Army was then instructed to seize all Fenian weapons and ammunition and prevent more border crossings . Further instructions on 7 June 1866 were to arrest anyone who appeared to be a Fenian . Ironically , though they did nothing to advance the cause of Irish independence , the 1866 Fenian raids and the inept efforts of the Canadian militia to repulse them helped to galvanize support for the in 1867 . Some historians have argued that the affair tipped the final votes of reluctant Maritime provinces in favour of the collective security of nationhood , making Ridgeway the “ battle that made Canada . ” In June 2006 Ontario ’ s heritage agency dedicated a plaque at Ridgeway on the commemoration of the 140th anniversary of the battle . Many members of today ' s Canadian army regiment , The Queen ' s Own Rifles of Canada , return to the Ridgeway battle site each year on the weekend closest to the June 2 anniversary for a bicycle tour of the battle sites . Alexander Muir , a Scottish immigrant , author of the former Canadian national anthem , " The Maple Leaf Forever " and member of the Orange Order , fought at Ridgeway with the Queen ' s Own Rifles . A Fenian commander was Brigadier General Thomas William Sweeny , who was arrested by the United States government for violating American neutrality . Nevertheless , he was soon released and served in the Regular Army until he retired in 1870 . The total casualty figures for the Fenian Raids into Canada 1866 , including deaths from disease while on service in both Canada West ( Ontario ) and Canada East ( Quebec ) , were calculated by the Militia Department in 1868 as 31 dead and 103 wounded or struck by disease ( including a female civilian accidentally shot by the militia . ) Pigeon Hill Raid ( 1866 ) . After the invasion of Canada West failed , the Fenians decided to concentrate their efforts on Canada East . However , the American government had begun to impede Fenian activities , and arrested many Fenian leaders . The Fenians saw their plans begin to fade . General Samuel Spear of the Fenians managed to escape arrest . On June 7 Spear and his 1000 men marched into Canadian territory , achieving occupancy of Pigeon Hill , Frelighsburg , St . Armand and Stanbridge . At this point the Canadian government had done little to defend the border , but on June 8 Canadian forces arrived and the Fenians , who were low on arms , ammunition and supplies , promptly surrendered , ending the raid on Canada East . Mississquoi County Raid ( 1870 ) . This Fenian raid occurred during 1870 , and the Canadians , acting on information supplied by Thomas Billis Beach , were able to wait for and turn back the attack . Pembina Raid ( 1871 ) . Fenian John O ' Neill , after the failed 1870 Fenian invasion of Canada , had resigned the Senate Wing then joined the Savage Wing . In return he was given a seat on the Savage Wing governing council . In 1871 O ' Neill and an odd character named W . B . O ’ Donoghue asked the Savage Wing Council to undertake another invasion of Canada across the Dakota Territory border . The Council , weary of Canadian adventures in general and O ’ Neill in particular , would have none of it . O ' Neill ' s idea was turned down , but the Council promised to loan him arms and agreed they would not publicly denounce him and his raid . O ' Neill resigned from the Fenians to lead the invasion , which was planned in Saint Paul , Minnesota , to invade Manitoba near Winnipeg . About 35 men , led by John O ' Neill , William B . O ' Donoghue , and John J . Donnelly , hoped to join forces with Louis Riel ' s French - Indian Métis . On October 5 , O ' Neill ' s force managed to capture a Hudson ' s Bay Company post and a Canadian customs house just north of the international border . . . or so they thought . A U . S . survey team had determined the border was two miles further north , placing the Hudson ' s Bay post and the customs house both inside U . S . territory . O ' Neill , J . J . Donnelly and ten others were taken prisoner near Pembina , Dakota Territory by U . S . soldiers led Captain Lloyd Wheaton . The farcical raid was doomed from the very start . It actually took place inside the United States , and the Métis under Riel had signed a pact with the British just as the invasion began . Riel and his Métis captured O ' Donoghue and gave him to U . S . authorities . In a somewhat muddled federal response , O ' Neill was arrested twice - once in Dakota and once in Minnesota - but was released and never charged for " invading " U . S . territory . The men captured with him were released by the court as simply " dupes " of O ' Neill and Donnelly . Agitation in Pacific Northwest . The Fenian Brotherhood organized openly in the Pacific Northwest states during the 1870s and 1880s , agitating to invade British Columbia . Although no raids were ever launched , tensions were sufficient that Britain sent several large warships to the new railhead at Vancouver , British Columbia for the celebrations opening the Canadian Pacific Railway in 1886 . Results and long term effects . Support for the Fenian Brotherhood ' s invasion of Canada quickly disappeared and there was no real threat after the 1890s . Nevertheless , the raids had an important effect on all Canadians . The Fenian raids caused an increased anti - American feeling in Canada and the Maritimes because of the U . S . government ' s perceived tolerance of the Fenians when they were meeting openly and preparing for the raids . The raids also aroused a martial spirit among Canadians by testing the militia ' s strength . Because of their poor performance , the militia took efforts to improve themselves . This was achieved without the huge cost of a real war . The greatest impact of the Fenian raids was in the developing a sense of Canadian nationalism and leading the provinces into a Confederation . This was shown to be necessary for survival and self - defence ; the raids showed Canadians that safety lay in unity . The Fenian raids thus should be viewed as an important factor in creating the country we know today as Canada .