There was no doctor in the Corps of Discovery. Instead, Meriwether Lewis trained under the most famous of 18th century physicians, Benjamin Rush. He then created a list and purchased his supply of medical drugs and surgical instruments for the journey.
The accidents and ailments recorded in members' journals are extensive and varied.
It is astonishing to think that only one person died on the Expedition—most likely of peritonitis from a ruptured appendix.