PERHAPS no American president wrote more letters to more correspondents about a wider range of subjects than Thomas Jefferson. It was as if he composed his life and world with pen and paper. Of all those letters, one stands out as the central document for the American exploration of the West. Dated in Washington 20 June 1803 but undoubtedly drafted earlier, Jefferson's letter of exploration instructions for Meriwether Lewis became the defining document, the fundamental charter for government exploration beyond the wide Missouri. Our friend and colleague Ted Carter knew that letter well because, as I will explain in a moment, an earlier version of it is here at the American Philosophical Society. In one letter Jefferson defined the nature and methodology of scientific exploration, made it a national priority, and then handed that mission to the United States Army. No single piece of writing had greater influence on the day-to-day business of exploration for the rest of the nineteenth century-and perhaps even into our own time-than the president's letter to Lewis. Some sixteen years after Jefferson wrote to Lewis, secretary of War John C. Calhoun busied himself preparing directions for the first government reconnaissance of the central Great Plains. At the end of those detailed guidelines, the secretary simply told Major Stephen H. Long to consult what Jefferson had written for Lewis. In not much more than a decade and a half, Jefferson's letter had become the acknowledged master plan for exploring the West.
We think of exploration as a journey through a physical landscape, a journey that has a beginning at some particular place along the route. But the most important beginnings are the ones made before leaving home. They are the explorations into the country of the mind. Exploration beginnings are most often found in questions because at heart exploration is about inquiry. Lewis and Clark-and all those who followed after them-questioned their way West. For most explorers in the Euro-American tradition those questions came as formal, written instructions. Think of those instruction documents as the program: exploration software to run expedition hardware. Such written instructions were nothing new for Jefferson and his contemporaries. England's Royal Society had been giving travelers and merchants lists of questions for nearly fifty years. But by the middle of the eighteenth century-thanks in large part to the Enlightenment's passion for orderly, rational inquiryexploration instructions took on a new shape and substance. Those instructions shifted attention from the exotic to the useful, from personal adventure to cooperative enterprise and careful observation, from individual glory to national power and imperial expansion.
That redefinition of exploration instructions was largely the work of Sir Joseph Banks and an intellectual-imperial circle that involved mariners, scholars, and bureaucrats in the Royal Society and the Admiralty. More than any other single figure, Banks embodied and defined Enlightenment exploration and its global reach. Patron, planner, and sometime participant in the Cook and Vancouver enterprises, Banks was what one contemporary called "the common Center of we Discoverers." For voyage after voyage, Banks wrote the instructions; others did the sailing.
Banks and Jefferson neither met nor corresponded but they had remarkably parallel lives and careers. Both were presidents of their nations' most distinguished scholarly societies-Banks at the Royal Society, and Jefferson at this venerable institution. Both were avid botanists, placing great emphasis on the discovery of new plants for foodstuffs and medicines. Both cultivated large and far-flung circles of correspondents. Both placed useful knowledge at the center of scientific pursuit. Both insisted that such knowledge was always to be in the service of imperial expansion. Both were patrons of the art and science of exploration. And both knew that exploration was a complex business demanding many minds and many hands. …