I te 27 o Whiringa-a-rangi 1911, ko O'Connell te Pihopa Tuatahi o Boston i riro hei Kaariana, a i whakawhiwhia ki a ia te taitara o Cardinal-Priest o S. Clemente. I pōturi ia ki ngā hui e rua o te pāpa i te tau kotahi rau e 1914
me te tau 1922, nā te mea me whakawhiti i te Moana-a-Kiwa i roto i te waka tere o te rā. I whakahe ia ki a Pope Pius XI, nāna i whakaroa te wā i waenganui i te matenga o te Pope me te tīmatanga o te hui. I te mutunga ka taea e O'Connell te uru atu ki te huihuinga 1939 i muri mai, ahakoa i taua wa kei te waatea te haerere rererangi.