A map of Lewis and Clark's track, across the western portion of North America from the Mississippi to the Pacific Ocean, in 1804, 5 &amp; 6.  Copied by Samuel Lewis from the original drawing of William Clark.  Published in Philadelphia in 1814 by Bradford and Inskeep.
Samuel Lewis
Library of Congress Geography &amp; Map division, Call Number <a rel="nofollow" class="external text" href="http://hdl.loc.gov/loc.gmd/g4126s.ct000028">G4126.S12 1814 .L4</a>.  Original upload was cropped and sharpened a bit.