Kammala jumla mai zuwa: A ranar 26 ga Yuni, 1861 Baxter ya shiga cikin yakin basasar Amurka, ya shiga 12th Massachusetts Volunteer Infantry a matsayin likitan likitan. Ya yi aiki har zuwa Afrilu, 1862, lokacin da aka nada shi a matsayin likitan likitancin soja a cikin Sojojin Potomac. Ya shiga cikin Kamfen na Peninsula, gami da Yaƙe-yaƙe na Yorktown, Hannover Court House, da
Bakwai Bakwai.