American teacher and botanist interested in the woody plants of the West Central States. Born in Bellefonte, Pennsylvania, George Letterman began his schooling at the State College in Center County but this was interrupted when he enlisted in the Union Army during the Civil War. Serving until the end of the war he crossed the plains of New Mexico before returning to Pennsylvania. Soon afterwards, however, he moved to Kansas in the hope of becoming a farmer (1869) but eventually settled in Allenton, Missouri where he taught in the public school system for 20 years. Not long after his arrival Letterman befriended the botanist August Fendler and he became interested in woody plants; in time coming to know George Engelmann as well. Collecting plant specimens in the area he was made a special agent of the Census Department of the US government in 1880 and in this role collected data about the trees and forests of Missouri, Arkansas, western Louisiana and eastern Texas. Later Letterman was also employed by the American Museum of Natural history to collect tree specimens in this region for the Jesup Collection of North American Woods. At the end of his career Letterman served for two years as superintendent of schools in St. Louis County.

Sources:
R.H. Mohlenbrock, 1982, "Illinois Solanaceae in the Missouri Botanical Garden Herbarium and Biographical Sketches of Some Collectors", Annals of the Missouri Botanical Garden, 69(2): 382-392
P. Spaulding, 1909, "A biographical history of botany at St. Louis, Missouri", The Popular Science Monthly, 74: 240-258.