Before he went exploring, he was Thomas Jefferson's private secretary
HE fact that Thomas 
Jefferson's best service to mankind was political has limited the world's estimate 
of... [DOC] [TLE] Lewis and Clark Expedition, The - Encyclopedia Virginia [PAR] Apr 8, 2013 ... Thomas Jefferson was an active member of this group, but he ... U.S. Army and 
his private secretary at the time, to serve as commander of ... As a result, by 1803 
it seemed that an American expedition to the West might be over before it began.