James D. Hardy was an American surgeon who performed the world’s first human lung transplant in 1963 and human heart transplant in 1964.

Born in Alabama in 1918, Hardy obtained his medical degree from the University of Alabama in 1942. He served in the army during World War II, then returned to the University of Alabama to complete his surgical training, and in 1955 was appointed chairman of the department of surgery at the University of Mississippi.

In 1963 Hardy transplanted a lung from a deceased donor into a dying patient, who lived for 18 days after the surgery. It was the first time a human lung transplant had ever been attempted. In the following year, he and his team replaced a 68-year-old man’s heart dying of heart failure with one from a chimpanzee. The chimpanzee heart kept the man alive for around ninety minutes before failing. Though it was ultimately unsuccessful, Hardy’s work paved the way for the first successful human-to-human heart transplant in 1967 by Dr. Christiaan Barnard.

Hardy invented several surgical techniques and tools that are still used today, such as the Hardy pump-oxygenator heart-lung machine. As department chair, he trained many surgeons who further advanced the nascent field of cardiac and thoracic surgery. After retiring from clinical surgery in 1980, he continued teaching and conducting research. He received many honors and awards for his pioneering work, including the American Medical Association Scientific Achievement Award in 1970. He died in 2003 and is remembered as one of the most innovative cardiovascular surgeons of the 20th century.