McCracken is born into two of the city’s most prominent Presbyterian industrial families. He was the son of a shipowner, Captain John McCracken and Ann Joy, daughter of Francis Joy, of French Huguenot descent. The Joy family made their money in linen manufacture and founded the Belfast News Letter. He is the older brother of political activist and social reformer Mary Ann McCracken, with whom he shares an interest in Irish traditional culture.
In 1792, McCracken helps organise the Belfast Harp Festival which gathers aged harpists from around Ireland, and helps preserve the Irish airs by having them transcribed by Edward Bunting. Bunting, who lodges in the McCracken’s Rosemary Lane home, is a classically trained musician.
McCracken becomes interested in republican politics from an early age and along with other Protestants forms the Society of the United Irishmen in 1795 which quickly makes him a target of the authorities. He regularly travels throughout the country using his business as a cover for organising other United Irish societies, but is arrested in October 1796 and imprisoned in Kilmainham Gaol in Dublin. While imprisoned with other leaders of the United Irishmen, he falls seriously ill and is released on bail in December 1797.
Following the outbreak of the Irish Rebellion of 1798 in Leinster in May 1798, the County Antrim organisation meets on 3 June to decide on their response. The meeting ends inconclusively with a vote to wait for French aid being passed by a narrow margin. A new meeting of delegates is held in Templepatrick on June 5 where McCracken is elected general for Antrim and he quickly begins planning military operations.
McCracken formulates a plan for all small towns in Antrim to be seized after which rebels will converge upon Antrim town on June 7 where the county’s magistrates are to hold a crisis meeting. Although the plan meets initial success and McCracken leads the rebels in the attack on Antrim, the Catholic Defenders group whom he expects assistance from are conspicuous by their absence. The mainly Ulster Scots rebels led by McCracken are defeated by the English forces and his army melts away.
Although McCracken initially escapes with James Hope, James Orr, and James Dickey and is supported in his month long period of hiding by his sister Mary Ann, a chance encounter with men who recognize him from his cotton business leads to his arrest. He is offered clemency if he testifies against other United Irishmen leaders but he refuses to turn on his compatriots.
McCracken is court martialed and hanged at Corn Market, Belfast, on land his grandfather had donated to the city, on July 17, 1798. According to historian Guy Beiner, his corpse is spared the indignity of decapitation in order not to provoke renewed agitation. He is buried in the Parish Church of St. George in Belfast, but a few years later the grave is demolished.
McCracken’s remains are believed to have been re-interred by Francis Joseph Bigger in 1909 at Clifton Street Cemetery, Belfast, alongside his sister Mary Ann. His illegitimate daughter Maria, whose mother is speculated to have been Mary Bodell, is raised by her aunt Mary Ann McCracken.