æz ðə juːnˈaɪɾᵻd stˈeɪts mˈoʊbɪlˌaɪzd fɔːɹ wˈɜːld wˈɔːɹ ˈaɪ, ðɪ ˌɪndiːˈænə fˈiːld ɑːɹtˈɪlɚɹi bɪkˌeɪm fˈɛdɚɹəlˌaɪzd æz ðə wˈʌnhˈʌndɹɪd fˈɪftiəθ fˈiːld ɑːɹtˈɪlɚɹi ɹˈɛdʒɪmənt, ænd ɐsˈaɪnd tə ðə fˈoːɹɾi sˈɛkənd ˈɪnfəntɹi "ɹˈeɪnboʊ" dᵻvˈɪʒən, wˌɪtʃ pɑːɹtˈɪsᵻpˌeɪɾᵻd ɪn sˈɛvɹəl mˈeɪdʒɚ bˈæɾəlz ɪn nˈaɪntiːnhˈʌndɹɪd ˈeɪtiːn.
As the United States mobilized for World War I, the Indiana Field Artillery became federalized as the 150th Field Artillery Regiment, and assigned to the 42nd Infantry "Rainbow" Division, which participated in several major battles in 1918.