"Capt. Lewis is brave, prudent, habituated to the woods, & familiar with Indian manners & Character.  He is not regularly educated, but he possesses a great mass of accurate observation on all the subjects of nature which present themselves here, & will therefore readily select those only in his new route which shall be new.  He has qualified himself for those observation of longitude & latitude necessary to fix the points of the line he will go over."
--Thomas Jefferson

From Lewis's letter inviting Clark to join the expedition
"Thus my friend you have a summary view of the plan, the means and the objects of theis expedition.  If therefore there is anything under those circumstances, in this enterprise, which would induce you to participated with me in it's fatiegues, it's dangers and it's honors, believe me there is no man on earth with whom I should feel equal pleasuure in sharing them as with yourself."
--Meriwether Lewis