Thomas Jefferson had long advocated sending an American-sponsored expedition to explore the region between the Missouri River and the Pacific Ocean. Although frustrated by the inability of George Rogers Clark in 1783–84, John Ledyard in 1788, and André Michaux in 1793 to fulfill this mission, Jefferson finally saw his dream become a reality with the dispatch in 1804 and safe return two years later of Meriwether Lewis and William Clark’s Corps of Discovery. The trip itself proved to be only half the battle, however. From almost the moment of their return, Jefferson hoped and expected that an authorized version of Lewis’s detailed journals would soon be published. In this he was to be greatly disappointed. Lewis contracted in 1807 with the Philadelphia firm of C. & A. Conrad & Company to have the work printed, but he never submitted a manuscript and, in consequence, nothing was accomplished prior to his suicide in 1809.

After Jefferson helped facilitate the conveyance of the orphaned documentation to Washington, D.C., Lewis’s former colleague and current executor William Clark took up the task of transporting it to Philadelphia and finding an editor. He eventually chose Nicholas Biddle, an intelligent young man who proved well-suited to the task. The outbreak of the War of 1812 and collapse of Conrad & Company in that same year delayed publication, but with the assistance of Paul Allen and a new publisher, Bradford & Inskeep of Philadelphia (aided by Abraham H. Inskeep of New York), the work was issued in two volumes in 1814 as a History of the Expedition under the command of Captains Lewis and Clark, to the Sources of the Missouri, thence across the Rocky Mountains and down the River Columbia to the Pacific Ocean. Performed during the years 1804–5–6. By order of the Government of the United States. For the next ninety years it would remain the only printed account based on Lewis’s journals.

Jefferson’s letter to Allen of 18 Aug. 1813, which he had originally composed as a stand-alone biographical essay, was placed just after the preface to the first volume of the work and entitled the “Life of Captain Lewis.” It has been cited and quoted on numerous occasions by historians, most often as evidence of Jefferson’s high regard for Lewis’s abilities and of the “depressions of mind” that beset the famed explorer throughout his adulthood. Indeed, the widespread unwillingness to lend credence to the possibility that Lewis might have been murdered is at least in part attributable to Jefferson’s interpretation of Lewis’s mental condition as unstable, both earlier and at the time of his death. Though saddened, Jefferson was clearly not surprised by reports that Lewis had died by his own hand, and the scholarly community has, by and large, followed suit (PTJ, 6:371, 13:382, 25:624–6; Jackson, Letters of Lewis and Clark, 2:392–7, 494–6; John Brahan to TJ and James Neelly to TJ, both 18 Oct. 1809; C. & A. Conrad & Company to TJ, 13 Nov. 1809; TJ to James Madison, 26 Nov. 1809; TJ to Bernard McMahon, 13 Jan. 1810; Vardis Fisher, Suicide or Murder? The Strange Death of Governor Meriwether Lewis [1962], esp. 179–82; Stephen E. Ambrose, Undaunted Courage: Meriwether Lewis, Thomas Jefferson, and the Opening of the American West [1996], esp. 476–81; James P. Ronda, Jefferson’s West: A Journey with Lewis and Clark [2000]).