The Photographic History of The Civil War: in ten volumes, Thousands of Scenes Photographed 1861-65, with Text by many Special Authorities, Volume 7: Prisons and Hospitals.
Francis Trevelyan Miller, Ed.

Lessons in ambulances

It was only after a great deal of experimenting with vehicles of various types, both two and four-wheeled, that the ‘Rucker’ ambulance was accepted toward the end of the war as the final development. It gave complete satisfaction. In the accompanying photograph appear types of the two-and four-wheeled ambulances. The former were soon found intolerable; they transmitted every bump and depression in the road by a direct jolt to the suffering patient. One great fault of the four-wheeled ambulances was their excessive weight in relation to their transportation capacity. The vehicle finally developed was the prototype of the improved ambulance now used in our army. The lower photograph shows a section of a the vast system of repairs. The tremendous importance of general hospitals was recognized by Congress in February, 1865, in giving the rank of colonel to department surgeons having more than 4,000 hospital beds under their charge, and of lieutenantcolonel to those having less than that number.

The murderous two-wheeled and merciful four-wheeled ambulance

United States ambulance repair shop at Washington