Fenian attacks had also been projected along the St. Lawrence, Niagara, and St. Clair frontiers, but here the militia were fully prepared for them, and the United States authorities took vigorous measures to prevent any repetition of the raid. Most of the Fenian leaders were arrested, and their followers, bitterly denouncing an unsympathetic Government, scattered to their homes.
The irrepressible O'Neil made one final attempt to invade Canada. In October, 1871, taking advantage of the unrest in Manitoba following the suppression of the Riel Rebellion, and counting on the enthusiastic sup-port of the half-breeds, he organized a raid from Pembina, on the Minnesota frontier. A Canadian force of approximately 1,150 men was about to march out from Winnipeg to attack O'Neil. Part of this force, 215 men, had just arrived from the east by the route followed by Wolseley the previous year. The action of the Canadian troops, however, was anticipated by the United States authorities. Under arrangements with the Canadian authorities, Lieut.-Col. Lloyd Wheaton, who was in command of the American troops at Fort Pembina, was instructed by the United States Federal Government to see that the neutrality laws were preserved. When the Fenians crossed the boundary he immediately followed them into British territory and promptly arrested the whole expedition. So ended the last attempt of the Fenian Brotherhood to strike at the ancient British enemy through Canada.