Charles Caldwell (May 14, 1772 – July 9, 1853) was a noted 19th-century U.S. physician who is best known for starting what would become the University of Louisville School of Medicine and is one of the earliest proponents of Polygenism in the United States. Early life Charles Caldwell was born on May 14, 1772 in Caswell County, North Carolina. His parents were Irish immigrants. Caldwell earned an M.D. from the University of Pennsylvania School of Medicine in 1796 while studying under Benjamin Rush. Career Caldwell practiced medicine in Philadelphia and was a lecturer at his alma mater, the University of Pennsylvania. He also edited the "Port Folio" (one of the day's primary medical magazines) and published over 200 medical publications. Caldwell was elected a member of the American Antiquarian Society in 1815. A significant number of copies of Caldwell's 18th and 19th century publications, including copies of the Port folio, survive in the collections of the AAS. Other institutions holding original copies of Caldwell's publications include the United States National Library of Medicine, and Harvard's Francis A. Countway Library of Medicine. In 1819, Caldwell left Philadelphia to join the fledgling medical school at Lexington, Kentucky's Transylvania University, where he quickly turned the school into the region's strongest. In 1821, he became a Francophile and convinced the Kentucky General Assembly to purchase $10,000 worth of science and medical books from France, many of which are still held at the university. Despite his success, his "abrasive" and "arrogant" temperament created enemies at Transylvania. The university's medical program would fold soon afterwards. The school dismissed him in 1837, and he then traveled with several colleagues to Louisville, where they created the Louisville Medical Institute. As at Transylvania, he made the new school an instant success, with its rapid growth into one of the region's best medical schools. However, he was forced out in 1849 due to a personal rivalry with Lunsford Yandell. Caldwell was one of the earliest supporters of polygenism in America. Caldwell attacked the position that environment was the cause of racial differences and argued instead that four races, Caucasion, Mongolian, American Indian, and Africans, were four different species, created separately by God. Caldwell was one of the earlier of the U.S. physicians who argued for polygenism; his work was subsequently cited by Josiah Nott in Types of Mankind and he was followed by physicians such as Samuel Henry Dickson and