What the Americans Knew
In order to prepare Meriwether Lewis to lead the expedition west, Thomas Jefferson sent him to Philadelphia to study with the nation’s leading scientists. These included physician Dr. Benjamin Rush; botanist Dr. Benjamin Smith Barton; Dr. Caspar Wistar, a physician and prominent anatomist and paleontologist; and David Rittenhouse, a noted astronomer and mathematician.
While there Captain Lewis received up-to-date scientific training. But unfortunately what he learned about the geography of Louisiana Territory and the lifeways of the Missouri and Columbia river tribes did not turn out to be of much help.
The British had mapped the western coastline north of San Francisco, and French and Spanish traders had described the Indian communities on the lower Missouri, but scholars knew very little about the North American interior where the expedition would spend most of its time.