wˌɛn ðə sˈɪvəl wˈɔːɹ bɹˈoʊk ˈaʊt, ɡɹˈɛɡ wʌz kəmˈɪʃənd ɐ kˈæptɪn ɪnðə θˈɜːd jˈuː.ˈɛs. kˈævəlɹi ˌɔn mˈeɪ fˈoːɹtiːn, wˈʌn θˈaʊzənd ˈeɪthˈʌndɹɪd sˈɪksti wˈʌn.
When the Civil War broke out, Gregg was commissioned a captain in the 3rd U.S. Cavalry on May 14, 1861.