During the Civil War, he served in the Union Army from 1862 to 1864 as a member of the staff of General Williams Rosecrans, commander of the Army of the Cumberland.
dˈʊɹɹɪŋ ðə sˈɪvəl wˈɔːɹ, hiː sˈɜːvd ɪnðə jˈuːniən ˈɑːɹmi fɹʌm wˈʌn θˈaʊzənd ˈeɪthˈʌndɹɪd sˈɪksti tˈuː tə wˈʌn θˈaʊzənd ˈeɪthˈʌndɹɪd sˈɪksti fˈoːɹ æz ɐ mˈɛmbɚɹ ʌvðə stˈæf ʌv dʒˈɛnɚɹəl wˈɪljəmz ɹˈoʊzkɹənz, kəmˈændɚɹ ʌvðɪ ˈɑːɹmi ʌvðə kˈʌmbɚlənd.