1 June 1866: The start of the Fenian Invasion of Canada & the Battle of Ridgeway.
The invading force of more than 1,300 Irishmen 'The Fenians' was determined to attack the British Empire on its own soil to divert British military resources from Ireland and cause the Empire International embarrassment. They met no resistance when they crossed the Niagara River on June 1 but by the time they reached Ridgeway a Canadian force was deployed in front of them with orders to engage and defeat them.
At Ridgeway the Canadians initially stood their ground by as the day wore on they broke ranks and became visibly disorganised. The Irish commander, Colonel O'Neill spotted their discomfort and quickly ordered a bayonet charge that completely routed the inexperienced Canadians. The Fenians took and briefly held the town of Ridgeway. Then, expecting to be overwhelmed by British reinforcements, they quickly turned back to Fort Erie where they fought a second battle - Battle of Fort Erie - against a small but determined detachment of Canadians holding the town.
The Canadian loss was 7 killed on the field, 2 died of wounds in the immediate days following the battle, and 4 died of wounds or disease later and 37 were wounded, some severely enough to require amputation of their limbs. O'Neill said he had four or five men killed, but Canadians claimed to have found six Fenian bodies on the field
A U.S. gunboat prevented reinforcements of 10,000 waiting to cross and join the invasion and the invading force of Fenians retreated back to Buffalo.
Thus ended a bizarre and unsuccessful attempt by the US based Fenians (many of them Irish veterans of the US Civil War) to attack Britain through Canada. While tactically well conducted there was no chance of success once the US authorities blocked supplies and reinforcements reaching Colonel O'Neill's men on the Canadian side of the border. This episode was a fiasco and a waste of badly needed money and resources where they could have had no lasting effect. O'Neill withdrew on 3 June to United States territory where he and his men were arrested.