Unknown History of Western New York:
In the years following the Civil War, thousands of Irish ex-pats who had come over to earn money in the U.S. military found themselves in a foreign land, now trying to do what they could to help their home country. They were known as the Fenian Brotherhood and, in 1866, they devised a plan to drive the English out of Ireland.
Kennedy says they were, "Civil War veterans, American veterans, but Irish nationalists who felt so strongly that the British needed to get out of their country 3,000 miles away that they crossed the river here and invaded Canada to hold it hostage until Britain left their country."
The plan was elaborate.
Erie County Historian Doug Kohler says, "They were going to invade across at Cleveland, and up the Champlain Valley, and this would be an attempt to cross and seize the Welland Canal and, you know, force England to its knees. They'd have to create an independent Ireland because the Fenians had struck all across southern Ontario. In the end, this is the only invasion that goes forward."