Imprisoned on numerous occasions, both North and South of the border, he embarked on a number of hunger strikes in order to secure his release.

[1] He stood as a candidate for the Irish Republican party Clann na Poblachta before leaving them as a result of their decision to go into government with Fine Gael.

[3] At the end of the War he was sentenced and held as a prisoner of the Free State in either Finner Camp or Drumboe Castle.

[6][7] In September 1926 McCool's IRA unit raided the offices of a landlord's agent in Donegal, taking away all records.

[8] McCool, and his co-accused, which included Peadar O'Donnell's younger brother Barney, received a sentence of six months imprisonment.

[13] The success Fianna Fáil and the IRA at this time encouraged McCool, writing to fellow republican Frank Ryan in 1932 he said that the crowd (at the Drumboe march) "did one's heart good after all the black years... the youth are with us and that's everything".

[10] McCool wrote to then IRA Chief of Staff Moss Twomey requesting permission to issue a statement, ahead of a planned Orange march in Donegal, denouncing imperialist displays.

[20] He was also selected to stand as an abstentionist Republican candidate for the Foyle Constituency in County Londonderry[21] where he received 3,031 votes.

[18] This result, along with the votes obtained by other Republicans in Northern Ireland was hailed as significant with the IRA proclaiming 'the fight in the North has been given new life'.

By September 1936 McCool and Jim Killeen (Adjutant General before being arrested in the Craobh Ruadh Club) were on hunger strike for political status.

[26] Upon release after serving his 5-year sentence in Belfast, McCool returned to Ireland and was quickly arrested by the Gardaí with the intention of interning him.

Representations were made to the Justice Minister, Gerald Boland, that since McCool had only been released from prison in Belfast that he should not be interned as he had effectively not been active and there was no evidence that he was a threat.

McCool and McNamee worked tirelessly and even attempted to renew contacts with Germany ahead of the planned campaign in Northern Ireland.

McCool and Pearse Kelly colluded in writing this document which was essentially an education program for Republican internees which was intended to ensure that the Curragh Camp became "..a school of training of leaders and fighters".

This was a radical program which put the common good ahead of private property rights, called for large unproductive landholding to be redistributed, planned for surplus farm produce to be sold at a price guaranteed by the State and promoted State banks and co-ops among other radical social and economic proposals.

[40] One internee, Derry Kelleher, noted that this period in the Curragh was where "I first heard the word 'revolution' in the powerful northern accent of Seán MacCumhaill".

The public was not notified by the Dublin authorities until 18 June 1943 that McCool was on hunger strike and, due to the censorship in place at the time his election literature was not allowed to refer to this issue.

[44] By July 1943 the issue of those on Hunger Strike in the Curragh was the subject of debate in the Dublin Parliament and a number of demands were made for their release.

From his prison cell McCool issued a letter "To the Electors of East Donegal" which said in part: Ireland can only assume the march to freedom when the people return to Republican allegiance and, by their support of the Republican ideal, demonstrate to England and the world that the Irish question is not a matter of the internal affairs of the British Empire, but the right of an ancient and historic nation to its complete and absolute freedom and independence.

[45] Despite the censorship in place, which meant that only McCool's name and Party appeared on the ballot paper with little or no media coverage of his policies or plight, he polled 1,961 votes in the Donegal East constituency.

[50] However, by July 1945 he was again arrested and charged with plotting to kill Seán Gantly, head of the Free State Special Branch.

[51] Gantly, who had taken the Free State side after the Treaty split, had become the nemesis of many senior IRA members after carrying out a number of high-profile arrests against them.

[52] The reorganisation of the IRA had seen the election of a new leadership which was primarily composed of those who had opposed McCool and Pearse Kelly in the Curragh and also contained Paddy McLogan.

By 1947 the Clann had won two by-elections and their campaigning had given hope to many Republicans who had become demoralised by a combination of the Curragh splits, the Stephen Hayes affair, and the lack of political direction within the IRA.

Added to this was the fact that many voters felt that Fianna Fáil had failed to live up to their early promise, this was exacerbated by Taoiseach de Valera's government being content to let IRA men die on hunger strike, particularly Sean McCaughey in Irish prisons.

[55] 1948 saw a general election in the Free State, one which Clann na Poblachta, spurred on by their by-election victories, presented a serious challenge to Fianna Fáil.

[56] While McCool did not manage to win a seat, the overall Clann na Poblachta vote meant that the party held the balance of power in Ireland.

In 1944, Ben Griffin and Sean MacCumhaill made an offer to Mark Byrne to buy a field which was within the town boundary of Ballybofey, but at the time the owner was unwilling to sell.

In 1946, as part of the 'Civic Week' celebrations in the Twin Towns a friendly match between Sligo and Donegal was held in Mark Byrne's field.

[59] On 1 May 1949 McCool died (at the relatively young age of 48) of a perforated gastric ulcer, shortly after Mark Byrne's field was secured for the GAA.