As April 1923 faded into May, the anti-Treatyites campaign against the National Army began to lose its potency. By then, it was more of a destruction of property than a felony against the person. A great number of republicans were captured and imprisoned, and more were demoralised by the adverse conditions they existed under in the mountainous terrain of the south and west of Ireland. After the death of IRA leader Liam Lynch in April 1923, Frank Aiken, his successor, prompted his comrades to stand down. It was becoming obvious that victory was not theirs.

Sources

https://www.theirishstory.com/2012/07/02/the-irish-civil-war-a-brief-overview/#.ZFVTCx17nVo

Weekly Dispatch (London) 29 April 1923

Irish Independent 17 August 1932