Born James McNally in Newry, County Down, Ireland on 6 February 1836. He joined the British Army at the age of 17 (enlisting under a false name) to avoid arrest for the battery of a police officer.
He served in India before returning to Ireland where he became a Fenian, being sworn into the Irish Republican Brotherhood in 1864. The following year he deserted, along with Martin Hogan, from the British Army in anticipation of an expected Fenian uprising.
On 10 February 1866, he was arrested by the police who discovered him hiding in a safe house in Dublin. They were betrayed by an informant, Patrick Curran.
Wilson, along with other military Fenians were tried, found guilty of desertion and mutinous conduct, and sentenced to death. However, this sentence was later commuted to penal servitude for life, and they were transported to Western Australia. In October 1867, Wilson and sixty one other Fenians began the long sea voyage on board the Hougoumont to Australia.
Life in Fremantle was hard. Wilson had been sentenced to penal servitude, and found the monotony and work involved so hard to bear that he wrote to a New York City journalist, John Devoy entitling his letter, A Voice From the Tomb after having been in jail for some nine years.
Devoy was moved enough by Wilson's description of the conditions under which he and his colleagues laboured to begin collecting money amongst the American-Irish community to organise their rescue. Enough money was collected and a whaling ship, the Catalpa, was purchased and George Anthony was hired to captain the ship.
In 1876, the Catalpa sailed to Western Australia and rescued Wilson and five other Fenian prisoners. Initially the Royal Navy sought to halt the progress of the Catalpa and recapture the men, but after being fired upon once, Anthony raised the American flag. After this, the British did not fire upon them again and the ship sailed unimpeded to New York, the journey taking some four months.
Wilson settled in Rhode Island, where he married and lived out the rest of his life. In 1920, Wilson met with Éamon de Valera who was touring the United States, trying to gain support for his Irish Republic. Wilson died in November 1921; his remains are buried in the cemetery on the grounds of St. Mary's Church in Pawtucket, Rhode Island.