[1] In 1969 he helped found Coiste Cearta Síbialta na Gaeilge, together with members of Sinn Féin.
[2] He has been involved in the production of a number of documentaries in Irish for film and television.
Often described as an independent Republican socialist, he helped organise the James Connolly Forum in Galway.
[3] He has campaigned against the Lisbon Treaty and for the preservation and development of the cottage in Ros Muc used by Patrick Pearse.
[citation needed] Seosamh was re-elected to Galway County Council for the Connemara electoral area in the 2009 local elections.