Rubuta ci gaba don wannan sakin layi - An tattara rukunin a cikin sabis na Tarayya a ranar 12 ga Yuli, 1861, kuma ya bar wurin zama na yaƙi, ya isa Potomac a ranar 25 ga Agusta. A ranar 21 ga Oktoba, an yi ta fama da babbar asara a tsakanin dukkan rundunonin Tarayya a yakin Ball's Bluff. A cikin bazara na 1862, an sanya shi wani ɓangare na II Corps na Army of the Potomac kuma ya bi shi a lokacin Kamfen na Peninsular, yana shiga cikin Yaƙin Bakwai Bakwai
, Tashar Savage, da kuma Glendale tare da rashin hasara. A watan Afrilu na 1862, an sanya Kamfanin Massachusetts Sharpshooters na 1st Company zuwa ga rundunar, yana aiki tare da shi har zuwa bazara na 1863. Kashe yawancin lokacin rani a Harrison's Landing, ya tashi a watan Agusta kawai a lokacin da ya rasa yakin na biyu na Bull Run. Daga nan sai rundunar ta shiga yakin Maryland, inda 'yan kungiyar suka yi tawaye da shi a yakin Antietam, inda suka rasa fiye da kashi 50% na mutanensa 600. A lokacin yakin Fredericksburg, an kiyaye shi daga babban harin a kan Marye's Heights kuma ya sha wahala kadan. Yaƙin Gettysburg ya sami rundunar ta shiga cikin hare-haren sojojin Arewacin Virginia a ranar 2 da 3 ga Yuli, 1863, tare da asara mai yawa. A shekara ta 1864, ƙarfin rundunar ya ragu, amma har yanzu yana fuskantar yakin basasa tare da aiki a yakin basasa, Spotsylvania, Cold Harbor, da kuma Siege na Petersburg. A ranar 22 ga Yuni, rundunar ta iya samun jami'ai 75 da maza. An kama wannan karamin rukuni a wannan rana lokacin da sojojin Tarayyar suka kewaye su a kan titin Urushalima. Wadanda suka tsira da wadanda aka ba su izini sun fita daga aikin tarayya a ranar 26 ga Yuli, 1864, tare da sabbin ma'aikata da sake shiga aikin da aka tura zuwa 20th Massachusetts Volunteer Infantry.