I just learned of the Army Medical Department Museum, at Fort Sam Houston, San Antonio Texas

Vehicles, including field ambulances, hospital trains and aircraft showing the history of medical evacuation and treatment of the wounded in transit from 1775 to present.

http://www.history.army.mil/news/2015/150300a_spurgeonNeelAward.html

Recently acquired artifacts contributed to the Museum through the Foundation are a 1955 Willys MD-A, M170 Front Line Ambulance, an H13 D Model (Korean War) helicopter, and a UH1 Huey from the early Vietnam War.

1953 US Army Medical Services car

For more: http://ameddmuseum.amedd.army.mil/gallery/vehicles.html

The original U.S. Army Medical Museum was founded as a research facility in Washington, D.C., in 1862. Today, the institution is known as the National Museum of Health and Medicine of the Armed Forces Institute of Pathology at Walter Reed Army Medical Center. In 1920, our Museum was re-established at Carlisle Barracks, Pennsylvania, with the Medical Field Service School. In 1946, the School and Museum were transferred to Fort Sam Houston, Texas. In 1955, the Museum received its designation as the U.S. Army Medical Department Museum from the Surgeon General of the Army.

The details of how the wounded were moved, from horse drawn wagons, then trains, through Jeeps to helicopters are very well presented along with genuine examples of many types of military ambulance transportation. Included is a hospital railroad car built in the 1950s and actively used in Korea. This car, which is remarkably well preserved, represents the final evolution of military medical transportation by rail. By the 1960s just about all injured troops were being moved by specially equipped road vehicles, helicopters and jet airliners.

http://www.txtransportationmuseum.org/history-rr-military.php