Buuxi weedha soo socota: O'Brien wuxuu ku dhashay Jersey City, New Jersey, bishii Maarso 7, 1879. Wuxuu dhigtay Dugsiyada Dadweynaha ee Magaalada Jersey, Akadeemiyada St. Aloysius Grammar School iyo Saint Peter's College. wuxuu ka qalin jabiyay jaamacada Fordham. Wuxuu bartay sharciga Dugsiga Sharciga ee New York, waxaana loo aqbalay qareenka wuxuuna bilaabay ku shaqeynta Jersey City. Wuxuu garsoore ka ahaa maxkamaddii labaad ee dembiyada, wuxuuna ahaa agaasimaha amniga dadweynaha ee Jersey City laga soo bilaabo 1917 ilaa 1921. Wuxuu ahaa wakiil ka tirsan
Shirweynihii Qaranka ee Xisbiga Dimuqraadiga 1920