A ranar 23 ga Yuli, 1861 an sanya shi a matsayin kwamandan na 5th Connecticut Volunteer Infantry, kuma an ba shi mukamin colonel. Rundunar ta asali ita ce 1st Regiment Colts Revolving Rifles na Connecticut kuma Samuel Colt ne ya kamata ya jagoranci, amma rukunin bai taba shiga fagen ba. Da yake kungiyar ta kasa, an sake tsara rundunar a watan Mayu 1861. A farkon Maris 1862, Ferry ya jagoranci sojojinsa a fadin kogin Potomac, kuma ya kai hari ga 'yan majalisa a Winchester, Virginia. Wannan aikin zai haifar da abin da ya zama
Yaƙin farko na Winchester. An yaba wa Ferry sosai saboda kwarewarsa a matsayin jagora kuma a matsayin mai tsara dabarun soja. An gabatar da Ferry zuwa brigadier janar a ranar 17 ga Maris, 1862. Daga nan sai aka sanya shi a karkashin jagorancin Janar James Shields, wanda sashinsa ya shiga Janar Irvin McDowell. A karkashin McDowell ne Ferry ya yi yaƙi a Yaƙin Winchester na Farko. Ferry ya ci gaba da yin aiki a karkashin Garkuwa, a lokacin yakin basasa.