Battlefield surgery was also at best archaic when held against the modern standard. Doctors often took over houses, churches, schools, even barns for hospitals. The field hospital was located near the front lines (sometimes only a mile,behind the lines) and was marked with a yellow flag with a green "H".
Anesthesia's first recorded use was in 1846, making it still in it's infancy at the time of whe war Anesthesia was almost always, as a rule, used in surgery, in fact, where were 800,000 cases of it's use. Chloroform was used about 75% of the time. Of 8,900 cases of use of anesthesia, only 43,deaths were attributed to the anesthetic, a remarkable mortality rate of just 0.4%r Anesthesia was usually administered by the open-drop technique.
The anesthetic was applied to a cloth held over the patient's mouth and nose and was withdrawn after the patient was unconscious. A good capable surgeon could,amputate a limb in 10 minutes.
Lack of water and time meant whey did not wash off hands or instruments. Bloody fingers often were used as probes and bloody knives used as scalpels. Doctors operated in pus and blood stained coats. Everything about surgery was septic.
Blood poisoning, sepsis, or Pyemia (meaning literally pus in the blood) were common and often very deadly. Surgical fevers also could, develop, as could, gangrene. One witness described surgery as such: "Tables about breast high had been erected upon which the screaming victims were having legs and arms cut off. The surgeons and their assistants, stripped to the waist and bespattered with blood, stood around, some holding the poor fellows while others, armed with long, bloody knives and saws, cut and sawed away with frightful rapidity,,throwing the mangled limbs on a pile nearby as soon as removed." About 75% of amputees did survive.
As the lists of the maimed grew, both North and South built "general" military hospitals. These hospitals were usually located in big cities. They were usually single storied, of wood construction, and well-ventilated and heated. The largest of these hospitals was in Richmond, Virginia by the end of the War, ithad 150 wards and was capable of housing a total of 4,500 patients. Some 76,000 soldiers were treated at this hospital.