Harold L. Loucks practiced medicine in the U.S. and Asia for many years. As a young man, he became a resident at Peking Union Medical College, and by 1930, he became Head of the Department of Surgery there. During World War II, he was interned by the Japanese for half a year before being allowed to repatriate to the U.S. In 1954, Loucks became the Director of the China Medical Board, and he used the position to help develop medical education throughout East Asia. With Mary Ferguson, he also established and maintained the Yu Wang Fu Association, a network of former PUMC colleagues.