Whakaotihia te rerenga e whai ake nei: I whānau a O'Brien ki Jersey City, New Jersey, i te Poutu-te-rangi 7, 1879. I haere ia ki nga Kura Kawanatanga o Jersey City, Academy of St. Aloysius Grammar School me te Whare Wananga o Saint Peter. I puta ia i te Whare Wānanga o Fordham. I ako ia i te ture i te Kura Ture o New York, i whakaaetia ki te kaari me te tiimata i te mahi i Jersey City. He kaiwhakawa ia mo te kooti taihara tuarua, a ko ia te kaiwhakahaere mo te ahuru o te iwi o Jersey City mai i te 1917 ki te 1921. He mema ia ki te
Ko te Huihuinga ā-Motu ā-Rōpū i te tau 1920.