Before 1898, the care of the sick and those injured in the Navy and other branches was in the hands of many different titles under the Navy Department. In the earliest days of the Navy, this care was placed upon the surgeon and the surgeons assistant while they were also assisted by various members of the crew.
The Hospital Corps of the United States Navy came into existence out of necessity. After an act of Congress, approved June 17, 1898, an organized unit of the medical department was established. Many different positions came out of this such as pharmacist, hospital steward, hospital apprentice, first class, and more. This also fixed and organized the pay and specified duties of those involved.
The index of Mirabellis 1939 Handbook
With the escalation of the war in Vietnam, the United States began sending more and more troops into South East Asia. This included sending many Hospital Corpsmen to military bases, hospital ships, and in hospitals all over Vietnam, Thailand, Laos, and Cambodia. Much like in previous wars, they performed emergency treatment in a variety of combat and noncombat conditions. They were assigned to small medical teams that provided care and health advice to Vietnamese civilians as well as United States Marines and other personel. Some were assigned as medical advisors to Vietnamese military units, which required that they live in small, poorly defended villages. Hospital corpsmen felt the Vietnam conflict on a very high level. Six hundred twenty were killed or critically wounded and another 3,353 were wounded in action. Awards for gallantry in action included 3 Medals of Honor, 29 Navy Crosses, 127 Silver Stars, 2 Legions of Merit, 290 Bronze Stars, and 4,563 Purple Hearts.