The early nineteenth century is known as a period of transformation in American Christianity (Gordon S. Wood called this ‘the time of greatest religious chaos and originality in American history’). The older formalist denominations – Congregationalists, Anglicans and Presbyterians – haemorrhaged, while newer expressions, especially Methodists and Baptists, flowered. Historians have investigated this ‘Second Great Awakening’ with an eye to the role that the Stone-Campbell Movement played in it. While Barton Stone's leadership has been emphasised, Douglas Foster brings to life that other central figure behind the movement: Alexander Campbell (1788–1866).

Part of Eerdmans's Library of Religious Biography series, which includes recent works on Henrietta Mears, Billy Graham and George Whitefield, Foster's study delivers on its promise to be the first critical biography of Campbell. Earlier accounts such as Robert Richardson's two-volume Memoirs (1868–70) and Eva Jean Wrather's three-volume life (2005–9) were full of detail but tended to be hagiographic in character. Due to many of Campbell's papers being lost, Foster relies on Richardson (who did have access to Campbell's archive), but he carefully interrogates Richardson's account, routinely employing a source critical approach.

Scholars of American religion will know of Campbell through the role he played in what Nathan Hatch famously labelled the ‘democratization of American Christianity’. From him and his father, Thomas Campbell, a cluster of denominations arose: Churches of Christ, Disciples of Christ and Christian Churches. But Campbell's theological contributions and relationships to other ecclesial movements may be less known. Those not familiar with Campbell will find that he has variously been viewed as a sectarian exclusionist and progressive ecumenist.

The book is organised into five sections, with the second (on Campbell's theological values) and third (on clashes) bearing much of the biographical load. Born in north-eastern Ireland, Campbell lived there for his first twenty years before a year in Glasgow, followed by immigration to the United States. While at the University of Glasgow, Campbell took a class on Thomas Reid's Scottish commonsense philosophy, which, along with Lockean epistemological influences, shaped him as a child of the Enlightenment. Campbell believed that the American context, with its democratic form of government and separation of Church and State, was ideal for restoring the original character of the Gospel and Christian life. While Campbell's reform included emphases on unity and the coming millennium, Foster zeroes in on how baptism by immersion to remit sins formed the lodestar of Campbell's theology. Campbell claimed at one point that ‘immersion and regeneration are two Bible names for the same act’ (p. 184). An avid Bible translator (Foster estimates that Campbell's version sold more copies in the United States than any other translation except the King James Version until 1901), Campbell's decisions in translation reflected his belief in baptismal immersion for remission of sins, rendering the Greek baptizo as ‘immerse’ instead of ‘baptise’. Some of his translation choices, combined with his outright refusal to use the word Trinity (‘it is not a scriptural term, and consequently can have no scriptural ideas attached to it’), led his critics to denounce him as a Unitarian (p. 98). Although Campbell's statements could appear contradictory, Foster claims that the Lunenburg letter articles of 1837 provide the best window into Campbell's central convictions. These writings take a more inclusive attitude toward the theological significance of baptism, favouring the open-ended ‘put on Christ’ rather than harping on immersion as what marked a Christian (p. xiii). Along the way, we perceive Campbell's shift from the Presbyterian Anti-Burgher Seceder Synod of his childhood to alignment with Baptists to his own movement of Disciples.

Campbell's profile grew through public debates, most notably with Robert Owen (religious sceptic and social reformer) and John Baptist Purcell (Catholic bishop of Cincinnati). He also reached a wide audience by establishing and editing two periodicals: the Christian Baptist and the Millennial Harbinger. Campbell's deep interest in the role of education as a means to restoring the ‘ancient gospel and order of things’ led him to found Bethany College in what is now West Virginia. His conviction of the need for cooperation among congregations resulted in the creation of the American Christian Missionary Society, the first national organisation for the restorationist Churches. Most students of American religion today know of Campbell through the Stone-Campbell Movement that formed in the 1830s. Yet Foster tempers this association: ‘Campbell's relationship with Barton Stone was always uneasy at best’ (p. 229). The denouement of Foster's story concerns the coming of the Civil War, which exposed Campbell's belief in the primacy of the ‘Anglo-Saxon race’ (though he was no fan of slavery) and became a harbinger of the posthumous split in his movement.

Foster's account grants fresh insight into one of the enduring challenges in American religious history, namely, the tension between union and fracture. Campbell's group epitomises this phenomenon, merging with Stone's movement but also exhibiting a history of rifts. Moreover, Foster's thorough examination of Campbellism illuminates the primitivist impulse, seeking to clear the accretions of the centuries that impeded God's word to his people. In the process, engaged readers may also gain a sense of that other pole in nineteenth-century Christianity – a draw to affirm tradition (the Oxford Movement and John Henry Newman's development of Christian doctrine were contemporaneous with Campbell). This fine study may have been strengthened at points by relating developments in Campbell's life and teaching to those in American political, social and economic life. For example, if the Stone-Campbell Movement is commonly associated with frontier revivalism, how does Campbell's work relate to the development of the American frontier, which is such an integral part of the story of American ‘civilisation’? Common perception holds that a strong anti-intellectual current existed on the frontier, and thus perhaps part of the significance of Campbell's work is how it functions as a counter-narrative to this stereotype. Further, while the book pledges to show Campbell's global influence, not much space is devoted to this facet beyond a short statement that a majority of the eight million in Campbell's movement today are outside the United States. One wonders: where and to what extent has this expression of Christianity spread and indigenised beyond the American national setting?

But Foster has already done more than enough in drawing together a composite profile and analysing the work of this foundational leader. Deeply researched and highly informative, his account holds Campbell's complexities in balance. Campbell is revealed to be an exponent of Christian republicanism, a founder of restorationism and a white supremacist. With such scope, the book will appeal beyond scholars of American Christianity to historians of the early republic and antebellum eras for perceiving the ways that religion shaped the nation – perhaps most notably in Campbell's and his followers’ confidence in America's special place in hastening the millennium.