In World War I under the Army's new federalization system, they were designated the 155th Infantry Regiment and served with the 39th Division.
ɪn wˈɜːld wˈɔːɹ aɪ ˌʌndɚ ðɪ ˈɑːɹmiz nˈuː fˌɛdɚɹəlᵻzˈeɪʃən sˈɪstəm, ðeɪ wɜː dˈɛzɪɡnˌeɪɾᵻd ðə wˈʌnhˈʌndɹɪd fˈɪfti fˈɪfθ ˈɪnfəntɹi ɹˈɛdʒɪmənt ænd sˈɜːvd wɪððə θˈɜːɾi nˈaɪnθ dᵻvˈɪʒən.