|The United States Congress, early in
1803, approved President Thomas Jefferson's request to send "an
intelligent officer with ten or twelve chosen men fit for the enterprise"
(1) to explore the trans-Mississippi West. Jefferson chose Captain
Meriwether Lewis, his personal secretary at the time, to head the
expedition, and instructed him to leave for Philadelphia at once.
Lewis's mission to that city was two-fold; one, to assemble necessary
supplies and equipment for the expedition, and two, to call upon
important scientists who would provide him with "a greater
familiarity with the technical language of the natural sciences,
and a readiness in the astronomical observations necessary for the
geography of his route." (2)
|| (1) Thwaites, Reuben
Gold, Original Journals of the Lewis and Clark Expedition
(New York, 1904-05), VII, 208. (2) Coues, Elliot, Ed., History
of the Expedition Under the Command of Lewis and Clark (New
York, 1893), I, xxii.