 Ramba uchinyora ndima iyi - Cooper akanyoresa muuto somurwi muLouisville, Kentucky muna 1861 pakatanga Hondo Yenyika Yose. Akaitwa Sergeant musi waNovember 15, 1861 uye akapiwa basa semutevedzeri wechipiri mu20th Kentucky Infantry musi waJanuary 24, 1862. Kubva muna Kukadzi kusvika muna Chikunguru 1862 aive Acting aide-de-camp ADC uye Acting Assistant Adjutant general AAG ye22nd Brigade ye4th Division muArmy yeOhio. Muhondo yeKorindeakati akaratidzira ushingi hunosvika pakuva asina kufunga mumushumo wapamutemo waColonel Thomas D. Sedgewick. Mumushumo wakaitwa naSedgewick pakuvamba mumwedzi mumwe chetewo, akati nezvaCooper: Asst. Adjt. Gen. Wickliffe Cooper, sezvakanga zvaitika nguva dzose, akaratidza ushingi hukuru. Kutonhorera uye kunyatsoita kwaakaita nzvero dzinoverengeka dzakarayirwa neni pakati pengozi hurusa zvinofanirwa kurumbidzwa kukuru. Muna July 1862 akaitwa ADC kuna Maj. General William Nelson. Muhondo yeRichmond Nyamavhuvhu 1862, akasarudzwa kuti apiwe rukudzo nemukuru wemauto eUnion. Akabatwa musungwa ndokusunungurwa musi waAugust 30, 1862 muRichmond, Kentucky, sechikamu chokutsinhana vasungwa. 