1 of 26 Anesthesia is dripped onto a cone that is held over the nose and mouth of a soldier during the American Civil War before a doctor amputates the man's leg. Circa 1861-1865. National Museum of Health and Medicine

2 of 26 Battered soldiers rest outside of a brick hospital building in Fredericksburg, Va. The soldiers had suffered injuries fighting in the Civil War's Battles of the Wilderness campaign. 1864. Buyenlarge/Getty Images

3 of 26 A medic talks with a wounded solider lying on a gurney during World War I. Circa 1915. Guelph Museums/Wikimedia Commons

4 of 26 A sailor suffering from a bloody head wound receives treatment from a doctor in Germany. Date unspecified. Vintage Images/Getty Images

5 of 26 An injured soldier is taken away on a field ambulance by a member of the Royal Army Medical Corps. Field Ambulance Cadets at this time often took on the duties of stretcher bearers, orderlies, and other jobs that did not require a qualified doctor. Date unspecified. Hulton-Deutsch Collection/CORBIS/Corbis via Getty Images

6 of 26 Royal Army Medical Corps medics help to treat a German solider who was hit in the face by British fire near Carnoy, France during World War I. 1916. Bettmann Collection/Getty Images

7 of 26 Red Cross worker Anna Rochester helps to provide an injured solider with a little relief by lighting his cigarette at a military hospital in Souilly, France during World War I. Circa 1917. National Library of Medicine/Flickr

8 of 26 Troops of the 511th Parachute Infantry Regiment carry a wounded soldier to an aid station at Manarawat on the island of Leyte during World War II. 1944. National Archives/Wikimedia Commons

9 of 26 Surgeons work on the leg amputation of an injured solider at 46th Portable Surgical Hospital in Tinkhawk Sakan, Burma during World War II. 1944. National Library of Medicine

10 of 26 A German combat medic gives first aid to a solider who was fighting on the front line and received a leg wound during World War II. 1940. German Federal Archives/Wikimedia Commons

11 of 26 A medical team at work on an injured comrade during the Battle of Normandy during World War II. 1944. Wikimedia Commons

12 of 26 An American Army doctor operates in an underground bunker surgery room behind the front lines in Bougainville, Papua New Guinea during World War II. The injured soldier had been wounded by a Japanese sniper. 1943. Department of the Army/Wikimedia Commons

13 of 26 A doctor with the Royal Army Medical Corps checks on a wounded soldier during World War II. 1944. Wikimedia Commons

14 of 26 A wounded American soldier of the 4th Division receives blood plasma after an injury during the Battle of Saipan in the Northern Mariana Islands during World War II. 1944. Keystone/Hulton Archive/Getty Images

15 of 26 Combat medics apply first aid to a wounded solider on a French beach during World War II. 1944. National Archives and Records Administration/Wikimedia Commons

16 of 26 Navy Flight Nurse Jane Kendiegh feeds an injured solider on a return trip from the battle of Iwo Jima in Japan during World War II. 1945. U.S. Navy/Wikimedia Commons

17 of 26 A solider lies on a stretcher as several combat medics provide him with first aid in France during World War II. 1944. National Archives/Wikimedia Commons

18 of 26 An American medic works with two Army nurses to administer blood plasma to a patient who was critically wounded by shell fragments at the Battle of Anzio in Italy during World War II. 1944. Margaret Bourke-White/The LIFE Picture Collection/Getty Images

19 of 26 A U.S. medic helps to treat a solider who was injured during the Allied invasion of Sicily during World War II as several women and a child look on. 1943. Ullstein bild via Getty Images

20 of 26 Wounded soldiers with the 3d Battalion, 16th Infantry Regiment, 1st U.S. Infantry Division, rest after storming the beach at Normandy, France during World War II. 1944. National Archives/Wikimedia Commons

21 of 26 American Captain Clarence Brott applies a cast to the leg of a soldier with a deep wound in his thigh inflicted by a shell fragment during World War II. 1943. National Library of Medicine

22 of 26 A civilian who was injured during the American invasion and bombardment of Inchon during the Korean War receives treatment from a U.S. medical orderly. 1950. Hulton-Deutsch Collection/CORBIS/Corbis via Getty Images

23 of 26 An American Air Rescue Service crew treats a wounded U.N. soldier who has suffered blood loss on one of an H-5G helicopter’s two outboard litters during the Korean War. Circa 1950-1953. National Museum of the U.S. Air Force

24 of 26 A stretcher carrying a wounded North Vietnamese Army soldier clears the trees on its way up to the Marine CH-46 Sea Knight helicopter during Operation Taylor Common during the Vietnam War. 1968. Jonathan Abel Collection, USMC/Wikimedia Commons

25 of 26 A doctor shouts out in desperation for a stretcher team as he treats a wounded soldier of the U.S. 1st Cavalry Division near Bong Son during the Vietnam War. 1966. Bettmann Collection/Getty Images