John Charles O’Neill, Irish-born officer in the American Civil War and member of the Fenian Brotherhood, dies on January 7, 1878. He is best known for his activities leading the Fenian raids on Canada in 1866 and 1871.

O’Neill is born on March 9, 1834, in Drumgallon, Clontibret, County Monaghan, where he receives some schooling. He emigrates to New Jersey in 1848 at the height of the Great Famine. He receives an additional year of education there and works various jobs. In 1857 he enlists in the 2nd United States Dragoons and serves in the Utah War (May 1857 – July 1858), apparently deserting afterwards to California.

In California, O’Neill joins the 1st Cavalry, and serves as a sergeant in the American Civil War with this regiment until December 1862, at which time he is commissioned as an officer in the 5th Indiana Cavalry. He is credited as being a daring fighting officer but believes he has not received due promotion, which leads to a transfer to the 17th United States Colored Infantry as captain. He leaves the Union Army prior to the end of the conflict, marrying Mary Crow, with whom he has several children.

While in Tennessee, O’Neill joins the militant Irish American movement, the Fenian Brotherhood, which eschews politics in favor of militant action to expel the British presence in Ireland. He attaches himself to the group led by William Randall Roberts, who wishes to attack Canada.

O’Neill, ranked as colonel, travels to the Canada–US border with a group from Nashville to participate in the Fenian raids. The assigned commander of the expedition does not appear, so O’Neill takes command. On June 1, 1866, he leads a group of six hundred men across the Niagara River and occupies Fort Erie.

The following day, north of Ridgeway, Ontario, O’Neill’s group encounters a detached column of Canadian volunteers, commanded by Lt-Col. Alfred Booker. The inexperienced Canadians are routed by the Civil War veterans. O’Neill withdraws back to Fort Erie and fights a battle against a detachment led by John Stoughton Dennis. With overwhelming numbers of Canadian forces closing in, O’Neill oversees a successful evacuation on the night of June 2-3 back to United States territory. He is later charged with violating the neutrality laws of the United States, but the charge is dropped.

The split between two factions of the Fenians remain, and penetration of O’Neill’s organisation by British and Canadian spies ensures that his next venture into Canada in 1870 is known in advance, and Canada is accordingly prepared. After the Battle of Trout River ends in a disorganized rout, O’Neill is arrested by United States Marshal George P. Foster and charged with violating neutrality laws. That leads to O’Neill’s imprisonment in July 1870 with a sentence of two years, but he and other Fenians are pardoned by President Ulysses S. Grant that October.

Though O’Neill renounces the idea of further attacks on Canada, he changes his mind at the urging of an associate of Louis Riel, William Bernard O’Donoghue. With the latter, and without the backing of the bulk of the Fenians, he leads an attack on the Hudson’s Bay Company‘s post at Pembina, Manitoba, on October 5, 1871. The area is then disputed between America and Canada. He is arrested by American troops.

Following his military career, O’Neill works for a firm of land speculators in Holt County, Nebraska. He dies of a paralytic stroke on January 7, 1878, and is buried in Omaha, Nebraska.