ɡɹˈɛɡ bɹˈiːfli wʌz ɪn kəmˈænd ʌvðə kˈævəlɹi kˈɔːɹ, ˈɑːɹmi ʌvðə pətˈoʊmək fɹʌm fˈɛbɹuːˌɛɹi tˈɛn, wˈʌn θˈaʊzənd ˈeɪthˈʌndɹɪd sˈɪksti fˈaɪv, tə fˈɛbɹuːˌɛɹi twˈɛnti fˈoːɹ, wˈʌn θˈaʊzənd ˈeɪthˈʌndɹɪd sˈɪksti fˈaɪv.
Gregg briefly was in command of the Cavalry Corps, Army of the Potomac from February 10, 1865, to February 24, 1865.