Whakaotihia te rerenga e whai ake nei: I te marama o Mei 1861, ka hoki mai ia ki te mahi hoia a te United States hei 1st Lieutenant i te 1st U.S. Cavalry Regiment. He mema ia o te ratonga Kaitaere auau tae noa ki tana whakataunga hei Koronela o te 1st Massachusetts Volunteers Infantry Regiment. I taua tūranga i whawhai ia ki Fredericksburg, Chancellorsville, Gettysburg,
Ko Mine Run, ko Wilderness, ko Spotsylvania. I whakawhiwhia e ia nga whakatairanga mo te rangatira i te US Army mo Chancellorsville me te koromatua mo Gettysburg. I whakauruhia ia ki waho o te ratonga o nga kaihauturu i te Mei 28, 1864.