Rubuta ci gaba ga wannan sakin layi - Farenholt ya shiga Navy a matsayin mai jirgin ruwa Afrilu 24, 1861, bayan shekaru 3 a cikin sabis na kasuwanci. Ya shiga cikin fadace-fadace da fadace-fadace a yakin Hatteras Inlet Batteries.
, Yaƙin Port Royal, Yaƙin Fort Pulaski, da sauransu da yawa. A ranar 22 ga Oktoba, 1862, yayin da yake aiki a matsayin memba na ma'aikatan bindigogi a cikin jirgin ruwa, Farenholt ya ji rauni sosai a yakin Pocotaligo, South Carolina kuma an sallame shi daga Navy. Ya sake shiga Rundunar Sojan Amurka a watan Fabrairun 1863 bayan da ya dawo da shi kuma an sanya shi a cikin mai lura da kusan kusan yau da kullum tare da kare Charleston, South Carolina daga Afrilu 1863 zuwa Afrilu 1864. Ya shiga cikin tawagar da ba ta yi nasara ba a Fort Sumter a watan Satumba, 1863. Kyakkyawan sabis ya sa aka nada shi a matsayin mai aiki a ranar 19 ga Agusta, 1864, kuma ya zama kwamandan jirgin ruwa na jirgin ruwa wanda aka haɗe da jirgin ruwa a cikin Sounds na Arewacin Carolina a wannan shekara. Ya kuma shiga cikin sake kama Plymouth, North Carolina, da kuma wasu alkawurra a kan Roanoke, Chowan, da Blackwater koguna da kuma kama Fort Fisher, North Carolina.