Rubuta ci gaba ga wannan sakin layi - Bayan barin Majalisa, O'Brien ya ci gaba da gudanar da harkokin kasuwancinsa. Ya yi aiki a matsayin wakili a Majalisar Dattijai ta kasa a shekara ta 1916
Ka yi haƙuri. Ya mutu a Brooklyn a ranar 2 ga Satumba, 1924, kuma an binne shi a Holy Cross Cemetery.