Shortly after his release from prison in 1870, he entered into a conspiracy with emissaries of the rebel Louis Riel to assist in a great uprising in the Canadian Northwest, in which the Indians and half-breeds were to be utilized. O'Neil was ready for anything, and consented to invoke Fenian aid in conjunction with Riel's rebellious plans, by participating in an invasion of Manitoba. He managed to obtain a few hundred stands of breech-loading rifles and a quantity of ammunition that had escaped seizure by the United States authorities at the time of the Fenian Raid of 1870, and with the assistance of Gen. J. J. Donnelly, he fitted out an expedition on the Minnesota frontier. He started from Port Pembina, Minn., on October 5th, 1871, to invade Manitoba and raise his standard, but had barely crossed over the boundary line when he was arrested, with his troops. All of their armament was seized and they were marched back as prisoners to Pembina and handed over to the United States authorities. They were indicted on charges of breach of the Neutrality Laws, but at the trial were acquitted on some slight technicality. This ended Gen. O'Neil's career as a filibuster, and becoming disheartened and discouraged by his failures, he began drinking heavily, and soon became a wreck, subsequently dying alone and miserable as the result of his excesses, "unwept, unhonored and unsung." CHAPTER VII. THE DAWN OF PEACE--THE VOLUNTEERS RELIEVED FROM FURTHER SERVICE--THANKED BY THE GOVERNMENT AND THE LIEUTENANT-GENERAL COMMANDING. The active militia of the Dominion which was called out for active service remained on duty wherever posted until all signs of danger had disappeared, and were then withdrawn by degrees, until on the 3rd of June all were released from duty and directed to return to their homes. The Honorable Minister of Militia, in his report of the military operations, paid the following tribute to the gallantry of the volunteer militia force on this occasion:--