Item History: In the spring of 1803, Meriwether Lewis began to purchase scientific and mathematical instruments for a pending expedition into the northwestern region of North America. Among the items he purchased from Philadelphia instrument maker Thomas Whitney were three pocket compasses for $2.50 each, and this silver-plated pocket compass for $5. It has a mahogany box, a silver-plated brass rim that is graduated to degrees and numbered in quadrants from north and south, a paper dial, two small brass sight vanes, and a leather carrying case. Whether Lewis purchased the silver compass for himself or intended it as a special gesture for William Clark is not known.
Following the instructions of President Thomas Jefferson, the Corps of Discovery, under the leadership of Lewis and Clark, ascended the Missouri River in May 1804 to obtain detailed information on the natural resources of the region, to search for a northwest passage, and to make official diplomatic contact with Indian leaders.
By the time they returned to St. Louis in September 1806, few of the instruments that were purchased for the trip had survived the journey. The pocket compass, however, was kept by Clark as a memento. He later gave the compass to his friend, Capt. Robert A. McCabe, whose heirs donated it in 1933 to the Smithsonian Institution.