John Melmoth Dow was a shipmaster, shipping agent and naturalist. Born in New York City in 1827, he joined the Panama Railroad Company. He made his first voyage to the Central American coast in 1851, and remained involved with Central and South American coastal trade as a ship captain until 1876. He was appointed commander of the steamer Constitution in 1853, and opened the Central American service of the Panama Railroad Company as commander of the steamer Colombus. He later became a shipping agent for the Pacific Mail Steamship Company. During his years as a shipping agent, Dow was captured and held hostage by revolutionist Pedro Prest án in 1885. He was arbitrator in the dispute between the Compagnie Universelle du Canal Interoceanique and the American Contracting and Dredging Company in their attempt to build the French Canal in Panama. Dow died in New York City in 1892.