The guys in green are the Fenian Brotherhood. They're Irishmen, mostly Catholics I believe, who live in the United States. And thanks to the whole hundreds of years of oppression at British hands thing, they hate the crap out of the British. About twenty years earlier, the Fenian leaders were back home in Ireland fighting the failed Rebellion of 1848. But once they'd fled to the U.S., they lucked the fuck out: the end of the American Civil War meant that there were a whole bunch of unemployed guys – with military training and a crapload of guns – who didn't have much to do. Thousands of them signed up for the Fenian plan: they would raise an army and invade the Canadian colonies —still run by the British in those days — as a way of pressuring the U.K. into giving up Ireland.
Now, at this point it had been decades since there had been any kind of military conflict north of the border, so these fellows in red were pulled together at the last minute from all over Southern Ontario — many of them coming from the intensely Protestant, Catholic-hating city of Toronto. They were mostly young and inexperienced volunteers — shopkeepers and students, store clerks and farmers. Some of them got to practice firing their weapons the day before. Most didn't. And before they knew it, it was almost dawn, and they were marching across the open fields toward the highly skilled Fenian defenders.
Yet somehow, things got off to a good start. As the Fenians opened fire, the Canadian lines held; some of the Irishmen were even forced back. But then something — no one has ever been sure exactly what — went wrong. The Canadians became confused, mistakenly thought a retreat had been ordered, and started to head in the opposite direction. The Fenians seized their opportunity and drove the rest of them off. They'd won the Battle of Lime Ridge.
But the Canadians had already done enough. Hundreds of Fenians had been deserting their army since day one and the unexpectedly strong (if rather confused) resistance didn't help. As more of our troops poured into the area, the Irishmen panicked. They fled back across the river as quickly as they could: jumping onto logs and rafts or swimming for the other side. The Americans were there waiting for them on the far shore, ready to confiscate their weapons and send them back home.
The invasion proved to be one of the defining moments in the history of our country. That ragtag group of volunteers had been the first truly Canadian army (that is, without British commanders) to ever march into battle. The whole episode — the nationalist pride and the fear of the threat the Fenians posed — got people thinking all over the northern colonies. The very next year, they would band together, all the way from Ontario to Nova Scotia, and form their own brand new country: Canada was officially born.
Over the next few years, there would be more Fenian raids; none of them amounted to much, though it was a Fenian sympathizer who was hanged for killing Thomas D'Arcy McGee in 1868, the only Canadian federal politician ever assassinated.
In 1870, the very first war memorial erected in our city was unveiled near Queen's Park. (You can find it just on the other side of the west arm of University Avenue, tucked into the edge of the University of Toronto.) It was dedicated to the memory of the U of T students who volunteered to fight and die at the Battle of Lime Ridge. The New York Times reported that 10,000 people attended the ceremony.
You can read some fascinating first-hand accounts of the battle here, on Google books, by soldiers and reporters who were there that day. Just go to the bottom of page 43 and start reading. And there's a photo of the Queen's Own Rifles, a company who fought in the battle, here.
Oh and I should also mention that the battle is also frequently called the Battle of Ridgeway or the Battle of Limestone Ridge. You know, just in case you're sitting around with your friends someday getting drunk while discussing the intricacies of mid-19th century Irish nationalist movements and the factors that contributed to Canadian Confederation and then they're all like, "Battle of Ridgeway this" and "Battle of Ridgeway that" and you're all like, "Damn you Toronto Dreams Project Historical Ephemera Blog! I have no idea what they're talking about!"