Letterman, Jonathan(1824–72) surgeon; born in Canonsburg, Pa. An army surgeon, he tended soldiers injured during skirmishes with Native Americans (1849–62). Between 1862–64, he served as medical director of the Union's Army of the Potomac; his organization of the medical field service, including mobile hospitals and ambulances, laid the foundations for armies since then. In private practice in San Francisco following the war, he wrote Medical Recollections of the Army of the Potomac (1866).
The Cambridge Dictionary of American Biography, by John S. Bowman. Copyright © Cambridge University Press 1995. Reproduced with permission.