In early America, South Carolina was unusual in two respects. It was the first mainland colony where enslaved Africans became a majority of the population, a transition that occurred by the first decade of the eighteenth century. And, apart from Catholic-founded Maryland, its proprietors were the earliest to endorse religious toleration. In the 1660s, when the colony came into being, its organisers ignored the Clarendon Code. Doing so enabled them to recruit colonists of various persuasions – New England ‘Puritans’, often with ministers in tow; Huguenots from France; Scots and Scottish Irish who brought with them versions of Presbyterianism; planters or would-be planters from Bermuda and Jamaica, some of them Anglicans but others linked with Dissent. The economic benefits were substantial. Even after the colonial government accorded the Church of England a special status (1706), Scottish Presbyterians, New England-style Congregationalists and Quakers continued to flourish.

To this mixture, the Scottish-born minister Archibald Simpson (1735–95) brought Reformed orthodoxy, hostility to Anglicanism and a piety that he owed in part to the English evangelist George Whitefield. At an early age (perhaps by the time that he was eleven), Simpson was reading devotional manuals and undergoing a conversion modelled on what he learned from them, a conversion that eventually prompted him to choose ministry as his vocation. In 1752 Whitefield re-entered Simpson's life when he enlisted the young minister to emigrate to Georgia and work at Bethesda, an orphanage that the great evangelist had founded in Georgia. Subsequently, Simpson moved to South Carolina. There, his preaching gained him invitations to serve a sequence of Presbyterian or quasi-‘independent’ congregations. Troubles of various kinds – among them a series of courtships that ended badly – persuaded him to return to Scotland, where he resumed his ministry in Port Glasgow. He went back to South Carolina one more time to tend to the plantation that he had acquired.

A fully ‘Atlantic’ book, Peter Moore's biography of Simpson rests, in the main, on an extraordinary source, the extensive diaries that Simpson began to keep in Scotland and continued during his years in South Carolina A few volumes seem to have disappeared, but ten survive ‘spanning thirty-six years, totaling some 3,500 pages and 1.5 million words’ (p. xxvii), a source that Moore is the first to exploit in its totality; he has also published two of the volumes dealing with South Carolina through the University of South Carolina Press. As Moore observes, the diary fits within the genre of spiritual journal that emerged in Britain in the early seventeenth century and attained a higher level of definition in the eighteenth. Fortunately for historians of local religion, Simpson used it to comment in detail on his practice as a minister on both sides of the Atlantic.

Saving souls was foremost in Simpson's understanding of his office, but as happened elsewhere in the colonies as well as in mid eighteenth-century Scotland, an evangelising ministry was always and everywhere inseparable from economic, social and cultural issues. For Simpson and, in turn, for Moore, slavery was the single greatest challenge to his understanding of divine law and the gospel promise. Too many of the male slaveholders who dominated local presbyteries had fathered children with female slaves and shrugged off the disciplinary rules so central to Scottish Presbyterianism. When it came to financing a parish, some of these men decided that the best means of doing so was to gift a certain number of slaves to a local church which, in turn, would collect the income earned from selling their labour to planters. To his dismay, Simpson found himself drawn into the daily workings of the slave economy and, eventually, the owner of slaves himself.

The deeper issue arose out of Simpson's commitment to an Evangelical ministry: slaves had souls, but was the Christ who sacrificed himself so that all could be saved almost meaningless in a racist society? Moore cites the well-known example of a planter who freed his slaves after being converted (though not by Simpson). But he was the exception; slavery persisted because it was the master key to economic gain and social status in South Carolina. Hence the emphasis in Moore's narrative of the ‘paradox’ of Simpson's ministry and of Evangelicalism in general: aspiring to convert everyone, but failing to do so.

The sobering specifics of Simpson's encounter with slavery notwithstanding, he also detailed in his diaries how he approached the final stages of life. In a superb chapter, Moore describes Simpson's understanding of death as a moment for confronting someone's identity as a sinner and securing (hopefully) the repentance that would signal the sincerity of a conversion. It is rare to encounter a devotional practice so richly described as it is here. Unexpectedly, the contradictions of the slave system give way to the contradictions of Evangelicalism itself. Indeed, this biography is full of surprises, another of them is the account (which I pass over) of Simpson's ministry in Scotland. For anyone interested in discerning first-hand the workings of ministry in a colonial slave society, this book is the place to begin.