1863. Private Milton E. Wallen, Co. C, 1st Kentucky Cavalry.
Private Wallen was wounded by a Minie ball while in prison. His arm was amputated and was beginning to heal well, but after a week he began to develop hospital gangrene in the amputated stump.
Hospital gangrene was very common back in the days before antiseptic practices. As opposed to the conditions considered to be forms of gangrene today (gas, dry, wet), "hospital gangrene" was largely caused by Clostridium spp., and was quickly fatal. As Clostridium are bacteria that thrive in the lower GI tract, hospitals with poor sanitation (and consequently widespread fecal contamination) have far higher rates of hospital gangrene death.
Source: jstor.org