John O’Neill was born in Drumgallon, Co. Monaghan, Ireland on the 9th of March 1834. He was born into a farming family the third child born to John and Mary O'Neill. His father, who contacted a virulent strain of scarlet fever from a neighboring family in need, died six weeks before young John was born.
His mother, unable to eke out a living in Ireland and fearful for her children’s survival, emigrated to the United States in the latter part of 1835 with two of her children and settled in Elizabeth, New Jersey. John stayed behind with his grandfather, a staunch supporter of Irish Nationalism who harbored a deep distrust and hatred of England and its unholy presence in Ireland. The grandfather saw to it that his grandson received a good basic education and also made sure that he was well versed in Irish history. In December of 1848, at age 14, imbued with his grandfather’s political views and mindset towards England, John left Ireland to join his mother and siblings in the United States.
After arriving in New Jersey he completed his formal education. His first job was with a Catholic publishing company as a sales representative. He traveled extensively throughout New Jersey, eastern Pennsylvania, Maryland and Virginia. After a number of years on the road he settled in Richmond Virginia, where in 1855 he opened a bookstore.
In order to meet other Irish exiles living in Richmond who shared his his antipathy towards England he joined the local branch of the Emmet Monument Association. The aim of the organization was to provide military training to young men who at a future date would use that training to rid Ireland of the English scourge. O'Neill took full advantage of the training he received.
In 1857 he sold the bookstore and enlisted in the Second United States Dragoons who were preparing to go west to quell a Mormon rebellion in the Utah Territory. Disillusioned with the lack of action, O'Neill went AWOL and headed west to San Francisco where he spent the next few years. At that time San Francisco was the new home for Irish political exiles, patriots and poets including Terence Bellew MacManus, Batholomew Dowling and John Mitchel. While living there O'Neill met his future wife Mary Ann Crowe, an Australian of Irish parents.
In 1859, having second thoughts about his desertion from the Dragons he turned himself in and, fortunately for him, was returned to duty without trial.
At the onset of the Civil War in 1861, O'Neill was stationed in San Francisco with the 1st United States Cavalry, formerly the Second United States Dragoons. He returned to the east coast with his regiment who had volunteered for action in the Union Army. In March through July of 1862 the regiment was engaged in the battles of the Peninsular Campaign launched by the Union army in an attempt to circumvent the Confederate Army in northern Virginia and capture Richmond the Confederate Capital. On June 27, at the battle of Caines Mill, O'Neill was promoted from sergeant to the rank of second lieutenant for gallantry
In 1863 he was promoted to the rank of first lieutenant in the Fifth Indiana Cavalry at Munfordville, Kentucky. Notwithstanding his less than stellar attitude towards his superiors, O'Neill was hailed for his courageous leadership in a successful Union assault on troops under Confederate commander John Hunt Morgan during Morgan’s campaign in Kentucky, Southern Indiana and Ohio in the Summer of 1863. In December of the same year he was given another citation for bravery at Walker’s Ford where he was wounded in the leg.
In the summer of 1864 he was appointed Captain in the 17th United States Colored Infantry . He was forced to resign in November of the same year because of his impaired physical condition, resulting from the wound he received in Nashville the previous year.
Late that same year (1864) he married Mary Ann Crowe and settled in Nashville, Tennessee. They had three children over a span of ten years. In keeping with O'Neill’s penchant for moving from place to place, each of the children were born in different states including Nashville, Tennessee, Washington D.C. and O'Neill in Nebraska.
In 1866 O'Neill joined the Fenian organization in a leadership role. When the organization finalized it plans to invade Canada and hold it hostage for Ireland’s freedom, O'Neill was a willing participant, anxious to strike a blow at England when or where ever the opportunity presented itself. In addressing the Fenian Convention in Philadelphia in 1876 he said:
I have always believed in striking at England wherever we could reach her, and wherever the English flag floats and the English government is recognized and there are English soldiers in arms to defend the flag and maintain the government. I hold that the Irish people, particularly the Irish Exiles whom her oppressive laws have driven from their native land, have a right to go there and make war on England.
General Tom Sweeny a native of County Cork was in charge of implementing the plan to invade Canada, which included a series of co-coordinated raids from mustering points in Chicago, Buffalo and Maine. Command of the Buffalo expedition was entrusted to O'Neill who crossed the Niagara River at the head of at least 800 men during the night of May 31, 1866. On the morning of June 1st. a regiment of Fenians captured Fort Erie for use as a defense perimeter. On June 2nd O'Neill came face to face with British forces at Ridgeway where he out-fought and out-witted and decisively defeated the British and their Canadian cohorts. Had it not been for the half-hearted approach of other Fenian leaders, the outcome would have been far different and would have put the continued British occupation of Ireland to the test.
In the end the invasion was halted by US authorities’ who prevented supplies and reinforcements from crossing into Canada.
During the following week other attempted crossing were stymied by the US army. O'Neill, who still believed that the plan as originally devised would succeed if properly executed, launched two other raids into Canada, the first in May of 1870 from Malone and the second in October 1871 from Georgestown, Minnesota to no avail.
After that he turned his attention to his other great passion; the resettlement of Irish families from the slums of eastern cities to the western plains. After travelling throughout the west in search of the best place to resettle he decided on Nebraska as it possessed an abundance of pure water, fertile land and millions of acres of free government land.
In 1874 O'Neill embanked on a lecture tour along the east coast, encouraging the poor Irish that they would have a better standard of living if they would resettle with him in Nebraska. He was totally convinced they had a lot more on common with rural America than the dire poverty and miserable centres which they then resided in.
The first Irish colony in Nebraska was set up in Holt County in the town that bears his name today - O'Neill, Nebraska. He had very ambitious plans and his Nebraska colonies in Holt and Greenley counties were seen by him as just the start of many that would cover the plains.
His legacy is in the communities that exist in Nebraska today. These settlements are thriving and successful farming communities. John O'Neill can claim credit for the spirit of generosity that is still part of these communities today.
n 1877 while on a speaking tour in Little Rock, John O'Neill the consummate Irish and American patriot, became ill and returned to his home in Nebraska. His condition continued to deteriorate and after been admitted to St. Joseph’s Hospital Omaha in November 1877 suffered a stroke and died on the 8th of January 1878.