Kammala wannan jumla: A shekara ta 1861, a farkon yakin basasar Amurka, shi ne Adjutant na Uku Artillery. Ba da daɗewa ba bayan haka, ya yi murabus don shiga ma'aikatan Janar Edwin Vose Sumner a matsayin babban "mai taimakawa sansani", yana samun matsayin Manjo. Ya kasance wani ɓangare na Sojojin Potomac wanda ya ga aiki a cikin Yaƙe-yaƙe na Yorktown, Williamsburg, Fair Oaks, Bakwai Pines, Tashar Savage, Glendale, Malvern Hill, Antietam, Fredericksburg (duk wanda ya faru a 1862), da kuma
Gudun Ma'adinai wanda ya kasance daga Nuwamba 1863 har zuwa Disamba 1863.