Whakaotihia te rerenga e whai ake nei: I noho a Mann i te hotoke e whai ake nei i te tari whakauru a te ope taua o Chicago; i tukuna nga kaiwhiwhi ki te whakakii i nga rarangi o te 39th. I te tau 1864 i whakawhiwhia te puhi ki te ope taua a James i raro i te rangatira a Colonel Thomas O. Osborn. I riro i a Mann ngā mahi a Osborn i muri i tana whara i te
Ko te Pakanga o Drewry's Bluff I whakatere te 39 ki tetahi tuunga paruru o te Rōpū me te hopu i tetahi rangatira rangatira. Mo ana mahi, ko Mann tonu i whakawhiwhia ki a ia hei rangatira pirihimana.