Titian Ramsey Peale, was an American naturalist and artist and the youngest son of the painter Charles Willson Peale. He was well-known for his participation as an illustrator in various scientific expeditions in the United States and around the world at the beginning of the nineteenth century and also for his beautiful drawings, product of his research on the Lepidoptera Americana, an order of butterflies. There is little knowledge and very few records of an enigmatic expedition to the Magdalena River in New Granada in which the young Peale participated in 1831. This article wishes to bring to light this expedition through the archival findings at the American Philosophical Society in Philadelphia in order to begin to understand this mysterious journey, the whereabouts of the graphic material and its relevance in documenting the history of foreign nineteenth-century travelers to Colombia.