It was named after the original Cumann na nGaedheal organisation which merged with the Dungannon Clubs and the National Council to form Sinn Féin in 1905.

The second Cumann na nGaedheal did not come into existence until more than a year later, on 27 April 1923 when the pro-Treaty TDs recognised the need for a party organisation to win elections.

The pro-Treaty wing of Sinn Féin had decided to break off and become a distinct party in late December 1922, but its launch was delayed until after the New Year as a direct consequence of the turmoil caused by the Irish Civil War.

Griffith and Collins died in August 1922 during the early stages of the Civil War, leaving Cosgrave to lead the pro-Treaty Provisional Government in the run-up to the formal establishment of the Irish Free State.

The Irish Unionist Alliance was dissolved in 1922, when many of its followers swung their support behind Cumann na nGaedheal, seeing it as less hostile to them than the anti-Treaty Republicans and the later Fianna Fáil.

Thus, when J.J. Walsh, Minister for Posts and Telegraphs, resigned in 1927 due to the government's lack of support for protectionism, he sent an open letter to Cosgrave, claiming inter alia that the party had gone ″over to the most reactionary elements of the state″.

Thus the murder indirectly led to Fianna Fáil's forced entry to the Dáil and in August 1927 the government narrowly survived a vote of no confidence.

For the first time the party now faced vigorous parliamentary (if not entirely constitutional) opposition in the Dáil, as Fianna Fáil also made significant gains.

Since the foundation of the state Dáil business had been relatively calm as the relatively small Labour party functioned as the official opposition in the absence of die-hard Republicans.