(WHTM) — Being wounded at any point in the Civil War was a gruesome experience. A bullet to an arm or leg usually meant amputation; the odds of surviving a torso wound were pretty close to zero. But to add to the misery, during the first year and a half nobody had anything remotely resembling an ambulance service. Soldiers would lie on the battlefield, sometimes for days, before being removed to a field hospital, by which time it was often too late.

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This began to change in the summer of 1862. Jonathan Letterman, Medical Director of the Army of the Potomac, devised the command structure for a dedicated ambulance corps, and on August 2nd, General George B. McClellan issued General Orders 147, creating the Army’s first official Ambulance Corps. The goals were threefold: establish coordinated evacuation of casualties, organize medical logistics, and establish division field hospitals. The orders placed command responsibilities on non-physicians, so doctors could concentrate on tending to the wounded.

One important improvement-instead of using whatever vehicles were at hand, the corps had a standardized ambulance. (A replica of one of these ambulances can be seen at the Spangler Farm in Gettysburg.) The wagons had springs to smooth out the travel.

The new system got its first test at the Battle of Antietam. The new plan was only partially in place; on the Union right, the Ambulance Corp had all casualties evacuated by the morning after the battle. On the left, casualties weren’t finally cleared for another 24 hours.

At Gettysburg, the Ambulance Corps had all wounded within Union Lines removed by early morning the day after the battle. (One of the main field hospitals was named Camp Letterman.)

The new Ambulance Corps spread through the Union armies. In 1864 Congress acted to create a permanent ambulance corps. But when the war ended, the Army’s medical department was reduced in numbers, the organization so carefully built up started to fall apart-especially after the law to create the corps expired in 1866. But the experience gained from the Civil War would be applied in future conflicts-and the Civil War ambulance design would remain in use until the internal combustion engine supplanted the horse.