In response to
William Drennan's proposal for a "benevolent conspiracy--a plot for the people", on 1 April 1791 McCracken resolved with
Samuel Neilson, John Robb, Alexander Lowry and
Thomas McCabe to form "an association to unite all Irishmen [...] for the restoration and preservation of our liberty and the revival of our trade". Those who gathered for the inaugural meeting in October, and who called themselves, at the suggestion of
Theobald Wolfe Tone, the
Society of United Irishmen, were men with whom McCracken and his family had been associated in Belfast through the Rosemary Street Presbyterian churches and the
Irish Volunteer companies. While his name does not appear in early records, McCracken was in the confidence of the Society's executive committee from the outset. By the time McCracken formally took the
United Irish pledge (or "test") on 24 March 1795 to "persevere in endeavouring to form a brotherhood of affection among Irishmen of every religious persuasion", and "to obtain an equal, full and adequate representation of all the people of Ireland", the Society was abandoning its hopes for parliamentary reform. It was just a week since the reform-minded
Lord Fitzwilliam was recalled as
Lord Lieutenant of Ireland after just 100 days in office, and just four days before trade in Belfast and Dublin shut down in "sullen indignation" at this departure. Under the newly repressive regime of
Lord Camden, a decided opponent of
Catholic emancipation and of all other concessions, thoughts turned increasingly toward the prospect of a French-assisted insurrection. In June 1795, with three other members of the movement's Northern Executive,
Thomas Russell,
Samuel Neilson and
Robert Simms, McCracken met with
Theobald Wolfe Tone who was
en route to exile in the United States (and France). At McArt's fort atop Cave Hill overlooking Belfast they swore the celebrated oath "never to desist in our efforts until we had subverted the authority of England over our country, and asserted our independence". Working parallel to the "uniting" efforts of Father
James Coigly, during the
Armagh Disturbances McCracken and other emissaries from Belfast travelled extensively in an effort to counter sectarian tensions with the Society's republican programme. For a time he lived in County Armagh, working amongst the Defenders with
Charles Teeling (and ranging as far south as
King's County), urging them to join the united movement and binding himself in substantial sums to meet the expenses of those hauled before biased magistrates by their Protestant neighbours. Nearer home, in Belfast and its hinterland in Down and Antrim, McCracken worked with
Jemmy Hope organising among Presbyterian tenant farmers, tradesmen and labourers. He also undertook the fraught task of seducing government militia and of carrying information between Belfast and Dublin. In September 1796
Lord Castlereagh personally presented Neilson, Russell, Teeling and five other prominent United men with warrants for their arrest and pursued McCracken. He was seized on 10 October and lodged with the others in
Kilmainham Gaol in Dublin. Serious illness, however, permitted his release on bail a little more than a year later, in December 1797. ==Rebel commander==