Time was a crucial factor on the battlefield. Civil War physicians first attended those troops with the greatest chance for survival. The lesser wounds were bandaged and the more seriously damaged limbs were amputated.
Victims of the deadlier abdominal, chest and head wounds were frequently left until last or left to die.
This order of attention to injuries predated a more formal process of sorting the wounded. By World War I, triage had become a standardized system.
Amputations were the most common surgery performed during the Civil War. There was some public debate over the frequency of the practice, but doctors defended the surgeries, having found the amputation of a shattered limb to be the fastest, most life-saving procedure.
Surgeons usually met first and conferred over the decisions to amputate. The Battle of Antietam, with its 23,000 casualties, was legendary for the number of limbs that were sacrificed.