Alongside lifelong friend Michael Collins, he was a prominent veteran of the Irish War of Independence. Subsequently, he served as a Teachta Dála (TD), Army Officer and Garda Chief Superintendent.
In the 1921 elections, he was elected unopposed to the 2nd Dáil as a Sinn Féin TD for the constituency of Clare. He supported the Anglo-Irish Treaty and voted in favour of it. He was re-elected unopposed as a pro-Treaty Sinn Féin TD at the 1922 general election. He resigned as a TD on 18 December 1922.
He died as a result of a motor accident in March 1965.
The Liddy Medal – the Garda Veterans Injury Award – is named in his memory. The medal is presented to retired Gardaí who were injured in the line of duty while in the Force.[1]