John Letterman was born in Canonsburg, Pennsylvania, son of a surgeon. He quickly followed in his father’s footsteps, graduating from Jefferson Medical College in 1849. He joined the Army as an assistant surgeon and served in Florida during the Seminole Wars, New Mexico during the Apache wars, and in California when the army fought the Utes. At the onset of the Civil War, he was assigned to the Army of the Potomac. His battlefield experience soon gained him prominence, such that McClellan gave him carte blanche to do “whatever was necessary” to reform the medical service.
Letterman took on his new assignment with zeal and passion. He observed the carnage and chaos of the medical service during the Seven Days battles June 25-July 2, 1862, and decided on changes.
He instituted a system of first aid stations near the front lines that could treat minor injuries, and perform triage, – a new concept of sorting the wounded and treating the serious wounds first, as well as simply offering comfort to those beyond medical help, to make best use of scarce medical resources. His system went into effect at the Battle of Antietam.
His system was adopted by the entire Union army, and officially by an act of Congress in 1864. The mortality rate fell from 33% in the peninsular campaign to 2% at Gettysburg, for those that made it to the hospital.
Letterman’s re-organization of the medical corps was swift and efficient. He records in a letter dated October 30, 1862:
“In order that the wounded may receive the most prompt and efficient attention during and after an engagement, and that the necessary operations be performed by the most skillful and responsible surgeons at the earliest possible moment… there will be established in each Corps a hospital for each division… with a Surgeon in charge, an assistant surgeon to manage food and shelter, and an assistant surgeon to keep records.”
Letterman also establisned new standards for surgeons accepted by the medical corps, requiring medical education or equivalent practical apprenticeship.
Little was known of mosquito born diseases in those times, but Letterman knew that when camps were made near swamps, illness increased. He directed the commanders, some of whom regarded him as a nuisance, that “camps whenever possible should be made near living moving streams, and not in the woods, but rather on open ground. Use of surface water or from holes only two to three feet deep, should be avoided.” He also established health practices for latrines and disposing of kitchen refuse.
In the crisis of Gettysburg, Letterman lamented that Meade and others had frustrated his orders, causing a lack of ambulances. “Lost supplies can be replenished, but lives are gone forever.” Seven horses were killed and five wounded that would have pulled ambulances, and eight ambulances damaged in the fighting.
Letterman remarked, “Many surgeons in civilian life are anxious to operate, but this is a very small portion of a surgeon’s duties – this is only learned by battlefield experience.” Letterman made further contributions during the Battle of the Wilderness, and the Battle of Mine Run. Unfortunately, his ideas and practices and those of his mentor William Hammond were ahead of their time, and ran afoul of the prevailing medical establishment. Hammond was court-martialed for banning the use of calomel or mercuric chloride – mercury was a common medicine given to purge the system. Later Hammond and Letterman were proven scientifically correct.
Letterman suffered personally when his young wife died of gastroenteritis, an infectious diarrhea. He grew depressed, and resigned from the army before the end of the war.
Restless, he moved to San Francisco, taking a job with railroad magnate Thomas Scott – but fell ill shortly after the move, and died at age 47. His contributions to medicine went largely unheralded for many years, and might still have escaped notice but for his memoirs published in 1867, and his letters and diaries preserved in the National Library of Medicine.