An obscure undertaking in its own time, the Lewis and Clark expedition has grown in the American imagination, acquiring an almost mythic stature. Arriving as the country commemorates the expedition's bicentennial, Across the Continent is not an exercise in demythologizing; rather, it is an examination of the explorers' world and the complicated ways in which it relates to our own. The essays collected here look at the global geopolitics that provided the context for the expedition and at the interest in science, shared by Jefferson, that not only grew from the expedition but, to an extent, justified its undertaking. Finally, the discussion considers the various legacies of the expedition, in particular its impact on Native Americans, and the current struggle over who will control the narrative of the expansion of the American Empire.