Saint-Memin, an aristocratic refugee from the French Revolution, produced drawn and engraved portraits in the United States between 1793 and his return to France in 1814.  The original portraits were often in watercolor or chalk and always profiles.  The images were created with the aid of a physiognotrace, a mechanical device which allowed the artist to accurately draw the sitter's profile.  A discussion of Saint-Memin's work is found at http://educate.si.edu/migrations/portrait/essay.html.

This image is often used to portray Big White (Sha-ha-ka), ca. 1766-1812 (Mandan (Numakaki)) who was encountered by Lewis & Clark on their expedition and who visited Washington, D.C. in 1806-1807 at their invitation.  The portrait is not Shahaka, but probably that of Montgomery Montour (Delaware (Lenni Lenape)), whose portrait was also drawn by Saint Memin in Washington in 1807.  Montour was visiting Washington to protest an 1804 treaty by which the Delaware were moved from their lands in Indiana to the Louisiana Territory.