From 1819 until 1820, Major Stephen H. Long led the first scientific expedition to the central Great Plains. Thomas Say, a founding member of the Academy, accompanied Long as the expedition's zoologist. Academy member Titian Peale served as artist and assistant naturalist.

Prior to their departure for this hazardous endeavor, the well-known artist Charles Willson Peale painted Long’s and Say’s portraits—but his motivation for the paintings is surprising. Peale commented that “...if they did honour to themselves in that hazardly expedition that they might have the honour of being placed in the Museum and if they lost their skalps, their friends would be glad to have their portraits.” Contrary to Peale's concern, the explorers returned unscathed .

See one of the portraits for yourself when you visit the museum! Peale's portrait of Thomas Say hangs in the reading room of the Academy’s Ewell Sale Stewart Library and Archives.