This volume charts the establishment and early growth of the American empire. It begins with the American Revolution, when colonists in the New World broke away from what they viewed as the corrupt and oppressive British Empire. Even as they articulated a critique of the British imperial system, many American revolutionaries dreamed of creating an empire of their own. Through official treaties, newspapers, letters and diaries, and a variety of other sources this volume traces how U.S. Americans pursued this ambition during their first two decades of independence, during which the United States added substantial amounts of land to their new nation. This volume also explores how people in the United States collided with others who jeopardized the realization of their imperial ambitions, principally Native Americans and rival European colonists. Finally, this volume considers the ideas which underpinned this process—ideas which insisted that the United States could build an empire which would promote the spread of republican government in the New World. This notion of the United States’ so-called Empire of Liberty would form the bedrock of Americans’ expansionist ideology for generations to come.