The 1803 Louisiana Purchase doubled the size of the United States and stimulated interest in the poorly understood western edge of the North American continent. At President Thomas Jefferson's request, Congress commissioned a 'Corps of Discovery' to be headed by Captain Meriwether Lewis, retired from the US Army, and Lieutenant William Clark, whom Lewis invited to share the command. The Corps left from St. Louis on May 14, 1804, and spent two years mapping the Pacific Northwest. Members, especially Lewis and Clark, described and sketched its flora and fauna and encountered its native inhabitants before returning to St. Louis on September 23, 1806.
In February 1954, the 150th anniversary year of the expedition's departure, Congressman Charles B. Hoeven of Iowa introduced a bill into the House of Representatives authorizing a Lewis and Clark commemorative stamp. Although the bill never got out of committee, it helped move the stamp to the 'top of the list' of subjects under consideration. In June 1954, Postmaster General Arthur Summerfield announced that a Lewis and Clark stamp would be issued on July 28 at Sioux City, Iowa, in Hoeven's district. Summerfield justified his choice of location by stating, "Sergeant Charles Floyd, a member of the Expedition, died and was buried" at Sioux City. Floyd died of appendicitis only three months into the expedition and is not pictured on the stamp. Numerous other cities more directly connected with the expedition and its principal members protested, but without success.
The stamp is denominated at 3-cent, which paid the domestic first-class letter rate. It was printed in violet brown ink on the rotary press in sheets of 200 that were divided into four panes of fifty stamps each. Charles R. Chickering was the designer. The vignette was engraved by Charles A. Brooks; the frame, lettering, and numerals were engraved by John S. Edmondson. Bernard DeVoto, a popular historian of the American West and an expert on the Lewis and Clark Expedition, was a consultant in the design.
Reference: National Postal Museum Library, Papers of the Third Assistant Postmaster General, Stamp Design Files, Folder for Scott #1063.