Rubuta ci gaba don wannan sakin layi - Tare da barkewar yakin basasa, Kristi ya sami alƙawari a ranar 21 ga Afrilu, 1861, a matsayin laftanan-kolonel na 5th Pennsylvania Infantry. Ya fito ne a ranar 25 ga Yuli a ƙarshen sabis na watanni 3 na rundunar. A watan Satumba, an nada shi a matsayin colonel na 50th Pennsylvania Infantry, kuma ya shiga cikin yakin Port Royal. Ba da daɗewa ba ya zama kwamandan Brigade na 1, 1st Division na IX Corps. A Chantilly
, ya dauki umarni na wucin gadi na sashinsa bayan mutuwar, Isaac Stevens. Ya koma umurnin Brigade na 1 kuma ya yi yaƙi a yakin Kudancin Mountain da Antietam kusa da Burnside's Bridge. Ba da daɗewa ba bayan Antietam an canja shi zuwa umurnin Brigade na 2 a cikin Division na 1. Wannan brigade ya jagoranci a yakin Fredericksburg. Kristi ya kasance a cikin umurnin Brigade na 3, 2nd Division a IX Corps a lokacin Siege na Vicksburg amma ya koma umurnin Brigade na 2 a lokacin Knoxville Campaign. A cikin bazara na 1864 an sake mayar da IX Corps zuwa Gabas ta Gabas kuma Kristi ya dauki umurnin 2nd Brigade a cikin 3rd Division kuma ya yi yaƙi a yakin basasa, Spotsylvania, Cold Harbor. Lokacin da sojojin Tarayyar suka kai hari ga ayyukan Confederate a Petersburg, an ji rauni Kristi. Ya bar filin ne kawai na ɗan gajeren lokaci kafin ya dawo ya jagoranci Brigade na 1, 3rd Division a IX Corps. An tattara shi a ranar 30 ga Satumba, 1864.