Rubuta ci gaba ga wannan sakin layi - Farkon yakin basasar Amurka ya katse ilimin Corson yayin da ya shiga cikin Kamfanin K na 4th Pennsylvania Infantry a watan Afrilu 1861, kuma ya fito a matsayin sajan a watan Yulin 1861. Komawa zuwa Penn a ƙarshen wannan shekarar, ya yi aiki a matsayin likitan likita a asibitin soja a kan Cherry da Brad Streets yayin da yake karatu a makarantar. Ya shiga cikin 6th Pennsylvania Reserves (35th Pennsylvania Volunteers) a matsayin mataimakin likitan tiyata a watan Maris na 1863 bayan ya kammala karatun digiri na MD, ya shiga cikin yakin Gettysburg, Ruwa mai Ruwa, Manassas Gap, Bristoe Station, Mine Run
, Tashar Rappahannock, Dajin daji, Spotsylvania, Arewacin Anna, da kuma Cocin Bethesda. An ba da takardun shaida ga babban jami'in da ya bambanta kansa a cikin Wilderness, Corson ya sake sakewa a watan Yuni 1864. A tashar Bristoe a ranar 14 ga Oktoba, Corson da mai kula da asibiti sun ceci wani soja da ya ji rauni sosai wanda ya bar tsakanin layin yayin da yake karkashin wutar bindigogi. Saboda wannan aikin, an ba shi lambar yabo ta girmamawa a ranar 13 ga Mayu, 1899. A watan Nuwambar 1864, ya zama jami'in likita a sansanin Discharge, wanda aka yi amfani da shi don fitar da sojoji, a Philadelphia.