Designed by United States Bureau of the Mint Chief Engraver Charles E. Barber, the coin did not sell well and less than a tenth of the authorized mintage of 250,000 was issued.

Between 1804 and 1806, its members journeyed from St. Louis to the Oregon coast and back, providing information and dispelling myths about the large area acquired by the United States in the Purchase.

The coins were, for the most part, sold to the public by numismatic promoter Farran Zerbe, who had also vended the Louisiana Purchase Exposition dollar.

Seeking to gain knowledge of the new possession, President Thomas Jefferson obtained an appropriation from Congress for an exploratory expedition, and appointed his private secretary, Meriwether Lewis, to lead it.

A great service Sacagawea rendered the expedition was to aid in the purchase of horses, needed so the group could cross the mountains after they had to abandon the Missouri approaching the Continental Divide.

While they did not find the mammoths or salt mountains reputed to be in the American West, "these were a small loss compared to the things that were gained".

[4] In addition to knowledge of the territories purchased by the US, these included the establishment of relations with Native Americans and increased public interest in the West once their diaries were published.

[6] In gratitude for their service to the nation, Congress gave Lewis and Clark land grants and they were appointed to government offices in the West.

[7] Beginning in 1895, Oregonians proposed honoring the centennial of the Lewis and Clark Expedition with a fair to be held in Portland, a city located along the party's route.

A long drive to gain federal government support succeeded when President Theodore Roosevelt signed an appropriations bill on April 13, 1904.

[1] Numismatic historians Don Taxay and Q. David Bowers both suggest that Barber most likely based his designs on portraits of Lewis and of Clark by American painter Charles Willson Peale found in Philadelphia's Independence Hall.

[13] Art historian Cornelius Vermeule, in his volume on American coinage, pointed out that some people liked the Lewis and Clark Exposition dollar as it depicted historic figures who affected the course of American history, rather than a bust intended to be Liberty, and that Barber's coin presaged the 1909 Lincoln cent and the 1932 Washington quarter.

Nevertheless, Vermeule deprecated the piece, as well as the earlier American gold commemorative, the Louisiana Purchase Exposition dollar.

[14] The Philadelphia Mint produced 25,000 Lewis and Clark Exposition dollars in September 1904, plus 28 more, reserved for inspection and testing at the 1905 meeting of the United States Assay Commission.

[7] Among Americans who displayed exhibits at the fair were prominent cartoonist and animal fancier Homer Davenport[19] and long-lived pioneer Ezra Meeker.

Q. David Bowers speculates that Dr. George F. Heath, editor of The Numismatist, who opposed such commemoratives, declined to run any press releases Zerbe might have sent.