[1] His family had a very strong republican tradition and he claimed to be the great-grandson of the United Irishmen folk hero Roddy McCorley, who was executed for his part in the 1798 rebellion.
During this time McCorley's brother Felix was Adjutant and Training Officer of the IRA's Antrim Brigade and served in Liverpool, England.
The Brigade's leaders, by contrast, in particular, Joe McKelvey, were wary of sanctioning attacks for fear of loyalist reprisals on republicans and the Catholic population in general.
In addition, McCorley was in favour of conducting an armed defense of Catholic areas, whereas McKelvey did not want the IRA to get involved in what he considered to be sectarian violence.
McCorley wrote later that in the end, 'the issue settled itself within a very short space of time, when the Orange mob was given uniforms, paid for by the British, and called the Ulster Special Constabulary' (USC).
The role of the USC (a temporary police force raised for counter-insurgency purposes) in the conflict is still debated, but republicans maintain that the organization was responsible for the indiscriminate killings of Catholics and nationalists.
[3] On 26 January 1921, McCorley, was involved in the fatal shooting of three Auxiliary Division officers in their beds in the Railway View hotel in central Belfast.
[6] Thereafter, there was what historian Robert Lynch has described as a 'savage underground war' between McCorley's ASU and RIC personnel based in Springfield Road barracks and led by an Inspector Ferris.
On 18 May 1922 in Belfast, McCorley and Woods men carried out an assault on Musgrave Street RIC barracks in which they captured the files and military plans of the police headquarters.
To escape from the subsequent repression, McCorley and over 900 Northern IRA men fled south, to the Irish Free State, where they were housed in the Curragh.
Both McCorley and Seamus Woods were severe critics of the Irish Free State inertia towards Northern Ireland after the death of Michael Collins.
In the 1940s, McCorley was a founding member of Córas na Poblachta, a political party which aspired to a United Ireland and economic independence from Britain.