As we have read previously, Military Medicine during the American Civil War of 1861-1865, was primitive at best. This was caused by the acceleration of Military technology, which vastly outpaced medicine. The advent of The Rifled Barrel in both Cannon and small arms increased injuries. Many of these injuries were traumatic in nature. A soldier shot in the arm or leg most often died of his otherwise treatable wound. The cause was due to two issues. Disease and Amputation.
Civil War Doctors on both sides were in short supply. Often, poorly trained Assistants were the bulk of treatment for injuries. They most often prescribed simple Amputation for limb injuries. In normal cases, a Union Medical Corps. may have had only 50 Doctors and hundreds of Assistants. During a major Battle, often thousands of injuries presented themselves at any given time. The cases were overwhelming.
Often, in cases of Amputation - The Patient was very much awake to experience the horrible procedure (thankfully most passed out). The use of Anesthesia was known and experimented with in England. The most common of which was Ether (a liquid which emitted a gas). Unfortunately, portions used were not properly measured. Often too little was not effective, too much would kill. Of the percentage of Patients subjected to Ether on the battlefield, 60% died from the gas.
The process of recovery was a more likely killer. A period of "superation" (or drainage) of the amputated lab was needed (air exposure). After which, a "skinflap" would be "realigned" over the would (seal). It was during this period, the chance of Sepsis and related infection would occur - and kill. It is estimated that there were 30,000 battlefield Amputations performed by The Union Army during The War.
In terms of disease, this was speculated at being a far more common killer of soldiers than bullets. Although Organizations such as The US Sanitary Commission existed to relieve many infectious causes, the massing of thousands of men together, with poor water supplies and often ill prepared food, all led to death by very curable illnesses today. The Civil War would lead to many changes in Field Medicine and better precautions taken in Troop health. But the cost was high. It is estimated that casualties on both sides due to disease and non-survival of injuries, was 300,000.