On July 5, 1803, Captain Meriwether Lewis of the First Infantry left Washington, D.C., and headed west. His destination was St. Louis, Missouri, where he was to take command, with his good friend William Clark, of the aptly named Corps of Discovery. President Thomas Jefferson had long dreamed of exploring the West, and on the day before Lewis set out from the capital, Jefferson doubled the size of the country, purchasing 820,000 square miles from France for 3 cents an acre. Jefferson planned the expedition partly to expand commerce in the young nation—he sought the “Northwest Passage,” a water route from coast to coast—but, just as important, to further scientific understanding. Lewis shared with his commander in chief a deep curiosity about the natural world, and the expedition set out with a presidential charge to discover the flora and fauna of the United States. Jefferson, as talented a scientist as has ever held the office of president, introduced Lewis to the leading natural scientists of the day, and they trained him to collect samples of plants and animals. Jefferson instructed the two commanders to record everything they could about the countryside—“the soil and face of the country, its growth and vegetable productions . . . the animals of the country . . . the remains and accounts of any which may be deemed rare or extinct,” he said. And so they did, plainly but accurately. Jefferson’s personal library, one of the largest collections in the country and later the nucleus of the Library of Congress, included copies of works by Linnaeus and John Bartram, along with many other scientific texts. Meriwether Lewis served as Jefferson’s private secretary for two years before leading the expedition west, and Jefferson undoubtedly introduced his protégé to those works. The Corps of Discovery, like the Bartrams and Peter Kalm, played an important role in the ongoing effort to document the natural heritage of the United States.
