He was an independent delegate to the 1917-18 Irish Convention in which he opposed John Redmond's compromise on Home Rule. By 1918 his involvement in all aspects of the Irish independence movement had deepened greatly. Although not known if he was actually a member of the Irish Republican Army (IRA), he was very active in the Irish War of Independence as a supporter, financially and otherwise, of the East Clare Brigade of the IRA and its legendary leaders, Michael and Conn Brennan.