The subject of empire and empires is now one of the most active fields of historical writing, and that is especially true in the context of religion. Throughout history, religions and religious ideas have contributed powerfully to making successive empires, and in turn, the history of those empires is crucial for understanding the development of religious systems worldwide.

In recent years, historians have become increasingly aware of the imperial character of American history, from colonial days through the modern era. Although Americans have often been reluctant to admit the fact of their empire, it has always been a reality, from initial contacts with Native peoples through later expansion into new territories in the Pacific and the Caribbean, and subsequently into the Cold War era. Throughout this imperial history, religion has played an essential role. Religious beliefs originally justified the colonial enterprises into the New World, while later generations claimed to trace the divine will in a Manifest Destiny to conquer the whole continent. In turn, missionary dreams provided the justification for overseas expansion, and often supplied the practical means for undertaking such ventures. Repeatedly too, imperial confrontations have affected the homeland, and have done much to form American both racial and religious stereotypes and nightmares.

But the relationship between religion and empire in the American context is anything but a story of cynical alliances between church and state, between faith and political power. To the contrary, religious beliefs have often provided the conquered with an essential basis for resistance, and have mobilized anti-imperial movements. Without understanding empire, we are missing a vital part of the history of American religion. Empire, in fact, is the missing dimension in that story. Acknowledging that fact is all the more urgent in a United States increasingly populated by the descendants of nations and societies that were themselves the subjects of that sprawling American empire.