Best Answer #9: as no suitable answer was received, here is our ‘best answer’:
Ensign Malcolm McKenzie, No. 5 Company, was the first Canadian to die at the Battle Of Ridgeway, June 2, 1866, aged 27 years. The memorial to this University Of Toronto student and volunteer militiaman is a tall stone monument erected in 1869 at the highest part of the Presbyterian Cemetery, Vansittart Avenue. It cost $750: each Oxford county township contributing $25 and Woodstock contributing $50. His burial place and his plaque is on the east side of the monument. On the west side of the same monument is the burial place and a plaque to Joseph W. Boyle, added in 1983.
 
On June 1, 1866, an invading group of 800 to 1000 Irish-Americans, with much battle experience in the American Civil War, had crossed the Niagara and landed a mile north of Fort Erie. They were members of the Fenian Brotherhood Society that from 1866 to 1870 made a series of raids into Canada. To over-simplify matters, the Fenian leaders believed that much of the English garrison in Canada was Irish, and would therefore not fight for England if the Fenians invaded Canada to free it from English rule and make it a republic.

Pushing west to Ridgeway, the Fenian troop then fought a matching number of ill-trained Canadian militia for two hours. Sadly, inexperienced leadership under fire turned the Canadian's initial advance into confusion and final retreat. Canadian casualties were 10 dead, 37 wounded and 4 taken prisoner. However, although now winning, the Fenians withdrew and occupied the town of Fort Erie while waiting to fight a larger Canadian force expected soon from Port Colborne. Somewhat late, about 22,000 militia and British regulars were now also heading by rail towards the Niagara peninsula. Not wanting another Alamo, the Fenian higher command sent boats to bring their invasion force of now about 700 back from Fort Erie. At that point, on the morning of June 3, American gunboats took the boats with the evacuated Fenians in tow and blocked any more illegal Fenian movement across the Niagara.

With 5000 Fenians still in Buffalo, the U.S. government was concerned that it could not control matters. The Americans therefore offered amnesty and free transport back to their homes to any Fenians who promised to abandon their expedition against Canada and obey the U.S. neutrality laws. That no Fenian was punished was a clever move that worked to end the affair without any U.S. politician losing the Irish vote. The Canadians were furious.

Source:
- Hereward Senior, "The Last Invasion Of Canada: The Fenian Raids 1866-1870," (Woodstock Public Library).