Over the last thirty years, the development of Atlantic history has imposed a thorough revision of both national and imperial histories and paved the way for rethinking the Age of Revolutions in a global context. In this article I argue, however, that this twenty-first century Atlantic and global approach does not coincide with the perspective of the early nineteenth-century American actors. They were thinking, in fact, in different geopolitical terms as over time it had become obvious to them that their place was America, North and South, and hence their distinctiveness lay in the hemisphere. It was within this hemispheric framework that they grasped how its peoples faced the challenges of transitioning from being colonials to leaders of independent nations, from subjects of European monarchies to citizens of American republics, from followers of overseas orders to home- and foreign-policy decision makers. As they coped with these major changes, the article concludes that Americans laid the foundations of the Western Hemisphere as a world region with its own history.