A frontier settlement on the Ohio River in Louisville, Ky, gave rise to the growth of inland trading in the early 19th century. Within the ensuing years, the forerunner of America's oldest medical school, in Louisville, was chartered in 1833, and the Department of Surgery was developed in 1837. Medical education at that time was a primitive process, but it was soon shaped into substantial form with the appointment of Samuel David Gross, MD, the second professor of surgery. Dr Gross was the most influential and respected surgeon in North America in the 19th century. While serving as the chair of surgery at the University of Louisville, he substantially changed the institution and placed it in the forefront of American medical schools. When he returned to Philadelphia, Pa, Dr Gross left the surgery program to the able leadership of his longtime protégé, David W. Yandell, MD.