Tuhia he tomokanga mō tēnei wāhanga - I te whakauru atu ki te ope taua i te Paenga-whāwhā o te tau 1861, ka noho a Kennedy hei rangatira o te Kamupene E, 2nd South Carolina Infantry Regiment, i raro i te kaitiaki o Camden, a Col. Joseph Brevard Kershaw. I te Pakanga Tuatahi o Manassas, i patua ia e te pōro Minie, ka whara kino. I te whakaoranga, i whakatairangahia ia ki te koronel i te wa i whakatairangahia ai a Kershaw ki te rangatira rangatira. Ko te mahi tuatahi a Kennedy i runga i te whakahau o te ope i puta i te pakanga i te Nine-Mile Road e tata ana ki Richmond, Virginia, i te Pipiri 1862 i te Peninsula Campaign. Whai muri i te whawhai i te Pakanga o Savage's Station
, he torutoru wiki te roa o tana mahi i te pāmahana. I hoki ia ki tana rerenga i te wa mo te pakanga o Maryland. I a Stonewall Jackson e whakangao ana ki Harpers Ferry, i te taha o Kennedy a Kershaw i te hopu i nga mea nui o Maryland Heights. I arahina e ia tana rerenga i te whakaekenga a Kershaw i te Pakanga o Antietam, i peia e ia tetahi waahanga o te Uniana II Corps i mua i a ia. Heoi, i whara kino ia i te whakaekenga tuatahi, i patua i roto i te waewae me te tendon Achilles i a ia e whiti ana i te taiepa rakau i te taha o te Hagerstown Pike. I te wa ano i ora ai ia mo te pakanga nui, i arahina e Kennedy te 2 me te 8 o South Carolina ki te tautoko a Gen. Howell Cobb i Marye's Heights, te arotahi o nga pakanga tino wera i Fredericksburg.