The Fenian Brotherhood was a secret society dedicated to the goal of freeing Ireland from British rule. The Fenians had formulated a plan whereby thousands of Irish veterans of the Civil War who had served with the United States Army would be recruited to conquer British North America and use it as a bargaining chip to gain Irish independence. On the night of 31 May 1866, a Fenian force commanded by John O'Neill, a former U.S. cavalry officer, crossed the Niagara River north of Buffalo, New York. After cutting telegraph lines and destroying a portion of the Buffalo and Lake Huron railway line, the Fenian force encamped at Frenchman's Creek to await reinforcements. Upon hearing that the Canadian militia was being mobilized, O'Neill advanced and posted his troops on high ground near the village of Ridgeway.
Two Canadian forces were assembled to counter the Fenian invasion. The first, commanded by Colonel George Peacock, consisted of three companies of the 47th Infantry Regiment, the 10th Royals, the Lincoln Militia, and two companies of British regulars. This 1,700-man force would advance from St. Catharines. The second force, assembled at Port Colborne under the command of Lieutenant-Colonel A. Booker, included the 13th Battalion from Hamilton, the Queen's Own Rifles from Toronto, and the York and Caledonia rifle companies, 850 troops in all. Colonel Peacock planned to trap the Fenians between the two Canadian contingents.
The plan was poorly executed, however, and Lieutenant-Colonel Booker's force engaged the Fenians before Peacock's troops had arrived. In the ensuing battle, Booker's troops held their own until Booker received erroneous information that there were Fenian cavalry units in the vicinity. The Queen's Own Rifles formed a square to meet a cavalry attack and were easy targets for the Fenian marksmen. Booker's troops suffered 10 killed and 38 wounded before O'Neill withdrew his army across the river to the American side.