WASHINGTON—In a stunning revelation that demonstrates the expedition’s deep cultural significance, historians at the National Archives announced Friday the discovery of sketches that depict the regional chain restaurants Lewis and Clark encountered during their journey across America. “These chain establishments soon became a familiar sight, and a welcome one on occasions when we were in the throes of great hunger, yet not of a disposition to hunt or fish,” Capt. Meriwether Lewis wrote in the newly unearthed journals, which contain the famed explorer’s drawings of fast food and casual dining franchises found in the early 19th-century American West, as well as descriptions of their reliable if uninspired appetizers of hardtack, dried tubers, and venison sticks. “In such places we made a middling repast upon boiled elk or warmed-over bison shank, always served to us in severely lit rooms of oppressive design. It was in this way, however, that we met the Indian known as Sacagawea, a hostess at a Culver’s near Fort Mandan who soon joined our expedition, acting as interpreter and enabling us to establish trade with various proprietors of all-you-can-eat buffets.” In addition to their insights into the Lewis and Clark Expedition, the sketches are said to provide definitive evidence that the restaurant chains Waffle House, Friendly’s, Whataburger, Steak ’n Shake, and Jack in the Box were all appropriated from Native American tribes.