His Raheen office served as a meeting place for the Volunteers and guns, documents and ammunition were stored there. However, the war led to a sharp decline in the fortunes of his farm. The execution of close friends such as Conor Clune of Quin in November 1920 and the subsequent devastating raids on his farm resulted in his playing a far more active role in Sinn Féin as a loyal supporter of the new TD for Clare, Éamon de Valera. For this he was imprisoned following his return from Britain as part of a Sinn Féin delegation which was publicising the Black and Tans atrocities.