Over the past few decades, the discipline of history has been undergoing a transformation not unlike the one caused by the social and cultural turns of the late twentieth century. Today, globalization and transnationalism are having a profound impact on the ways in which historians approach their subject, no matter their time period or geographical focus. One of the main beneficiaries of the global and transnational turns is imperial history, a subject that fell out of favor with the rise of subaltern studies but once again finds itself at the center of various historiographical innovations.

The history of American religion has been affected by these developments as much as any other field. A welcome addition to this new literature is Christian Imperialism, Emily Conroy-Krutz's history of American missionaries, specifically Protestants and even more specifically Congregationalists and Presbyterians, in the part of the early-national era that spanned the War of 1812 to the Mexican War. Conroy-Krutz has several objectives, all of which interweave to produce a compelling overall analysis about America's place in the world and how religion helped to shape it. “Much of the early years of the mission movement,” she explains at the outset, “would be spent trying to work out how religion, the nation, and empire ought to relate to each other” (xiv). Encompassing all this was a worldview of civilization and race that Conroy-Krutz aptly terms “hierarchies of heathenism,” which “ranked the different cultures and peoples of the world with an eye to their level of civilization or depravity, with the ultimate goal of determining who would be most likely to be converted by missionary evangelism” (20). This is an insightful innovation, though it is a shame it is not used to analyze missionary attitudes towards slavery, abolition, and colonization aside from a brief discussion in a chapter on Liberia. Foreign peoples could move up (or down) the hierarchy depending on their capacity for development, their adaptability to Western ways, and their receptivity to Christianity.

Contrary to conventional assumptions that the early-national United States was inward looking, Conroy-Krutz uses her investigation of missionaries to argue that “Americans in the early republic were not only focused on the continent but were thinking about the global” (2). This makes perfect sense. Americans always had one eye fixed on westward settlement, of course, but they also had extensive dealings—military, diplomatic, commercial, and, as Conroy-Krutz shows, spiritual—across the planet. (Fittingly, Christian Imperialism is published in a prestigious series on “The United States in the World” rather than a series on religious history.) In fact, as the causes of the War of 1812 show, the two outward impulses—to the west and across the oceans—were not entirely separate but instead interrelated phenomena. We have known this for some time, but Conroy-Krutz gives it a depth and sophistication that has otherwise been missing. Her missionaries not only traveled throughout the Western hemisphere but also to Africa and Asia, where they established missions and medical clinics with the intention of remaining indefinitely. They were, in some sense, the advance agents of globalization. One could argue that early-American merchants and whalers also traveled the globe, but they had monetary objectives that were based on self-interest. By contrast, missionaries were motivated by normative concerns about humanity that were grounded in morality. They did not simply want to trade with the rest of the world—they wanted to reorder it with the Bible but without necessarily conquering it by the sword and rifle. Though Conroy-Krutz does not exactly put it this way, American missionaries thus created an early prototype for the kind of informal, normative, non-territorial empire the United States created in the twentieth century.

Conroy-Krutz's most important scholarly intervention is her typology of imperialism and her deft discussion of the ways in which different types of empire, not just American, intersected but also competed with one another. Conceptually, she deploys “imperialism” as a process rather than “empire” as an entity or polity, which gives her analysis a great deal of flexibility. In essence, her book is about three types of empire: Christian, American, and British. Christian imperialism aimed to spread the word of God and the culture of Christ to non-Christian peoples around the world, as well as to the indigenous peoples of North America. American and British imperialism, on the other hand, aimed to spread the power of those particular nation-states. None was synonymous with another, though missionaries initially hoped to fuse together the power of church and state. American missionaries thought of their nation as a Christian society, and while they hoped to see the secular power of the state export the religious ideals of the faith, once abroad they discovered that the two were not the same and could even be at odds. An even greater irony, which Conroy-Krutz illuminates wonderfully, lay in the tensions between American and British power. Americans on the whole distrusted Great Britain, yet after 1815 their security and prosperity depended to some extent on the protective shield of the Royal Navy and a steady flow of inward capital investment from the City of London. These too are familiar stories, but Conroy-Krutz invigorates them by adding a fascinating religious dimension. American missionaries, it turns out, could be fierce critics of American expansionism on the continent (such as Indian removal) and U.S. foreign policy overseas; but even more, American missionaries often found themselves relying on British commercial and naval routes for access and protection.

In the end, Protestant missionaries were not so much American exceptionalists as Christian exceptionalists. They believed in a social and cultural power that transcended the United States, which makes the title of her book all the more appropriate and illuminating. Christian Imperialism is a superb addition to the burgeoning subfield of work that uncovers the religious aspects of America's engagement with the wider world.