Theodore Dunham was first to perform an island flap in 1892. His 2-stage procedure was done in a single stage several years later by George Monks who credited Dunham but received much of the recognition. Despite the important role that the island flap continues to play in modern reconstructive surgery, little is known about the life and career of Theodore Dunham. This article analyzes a variety of primary sources (publications, special collections, and interviews with his grandson) to chronicle Dunham’s discovery of the island flap in the context of medical education and surgical training in the late 19th century. Dunham published many articles on a wide range of topics but his most lasting contribution to plastic surgery was the island flap.