History of the Military Health System
Prior to the Civil War, medical care in the military was provided largely as a function of the regimental surgeon and surgeons mates. While further attempts were made to establish a centralized medical system, care provision was largely local and limited. The availability of effective treatment for disease and injury was, by modern standards, primitive. Significant changes began to occur near the time of the Civil War, when improvements in medical science, communications and transportation made centralized casualty collection and treatment more practical. Source: History of the Military Health System