West Central Africa was, numerically, the most significant region of embarkation for the transatlantic slave trade. Between 1500 and 1867, an estimated 5.7 million people from the region, situated between the African-dominated ports north of the Congo river and Benguela in southern Angola, were forced into ships bound for the Americas. This represented 45 percent of the total number of people (12.5 million) who were presumably shipped as slaves across the Atlantic. With Luanda, the capital of the Portuguese colony of Angola, the region also included the by far most important single port of embarkation in Africa.
Despite these overwhelming numbers and the rich documentation available in Angolan, Brazilian, and Portuguese archives, the slave trade from West Central Africa has long been neglected by historiography. Only from the late 1980s onwards did a series of groundbreaking monographs begin to study its history. They revealed a predominantly bilateral slave-trading system directly connecting West Central Africa to the Americas, and most notably Brazil, across the South Atlantic. Daniel Domingues da Silva’s book is the latest example of this historiography.
His study focuses on the last century of this trade, during which it reached its apex due to the rising demand for slaves in the Americas and Great Britain’s first abolitionist measures elsewhere in the Atlantic. Between 1780 and 1867, an estimated 2.8 million slaves were embarked in the region’s ports. The book is based on a meticulous analysis of the shipping data available in the www.slavevoyages.org database, to which Domingues da Silva has himself been a major contributor, and a series of additional quantitative sources. Its aim is to show how such a quantitative approach can offer new answers to some of the major issues debated in the historiography on the transatlantic slave trade, such as the relative importance of demand and supply, the slaves’ geographical origins and demographic profile, the goods used for slaving transactions, and the methods and experiences of enslavement.
The book makes at least three major arguments. First of all, it argues that the very high numbers of people exported from West Central Africa between 1780 and 1867 not only resulted from the increasing demand for African slaves in the Americas, most notably in Brazil, but also from first abolitionist steps taken by the British. After having made participation in the transatlantic slave trade illegal for all British subjects in 1807, Britain began to pressure other slave-trading nations into bilateral treaties that similarly banned the “infamous commerce” for their citizens, first of all for the regions north of the Equator. As a consequence, the center of gravity of the transatlantic slave trade, including ships and money, moved southwards to West Central Africa.
Second, the book consistently argues that African polities and traders in West Central Africa retained a large amount of control over whom they sold, when, and what for. If two-thirds of the slaves shipped across the Atlantic were male and most of them adults, this was not so much due to preferences of slave owners in the Americas, Domingues da Silva claims, but because West Central Africans preferred to keep slave women and children as agricultural workers, wives, and kin. When Britain’s abolitionist pressure made the South Atlantic slave trade illegal in the 1830s, however, the number of slave children rose dramatically (Chapter 4). Furthermore, Domingues da Silva suggests that African traders preferred to sell slaves during the dry season (May to August), when there was little work in agriculture and when most wars were fought (Chapter 2), and that they had significant influence over the value and composition of the goods they received in return (Chapter 5). Even if they refute some older views, these arguments are much in line with newer work on the transatlantic slave trade that stresses African agency.
The book’s third and main argument, by contrast, is far more controversial. Laid out in Chapter 3, it concerns the geographical origins of the slaves exported from West Central Africa. Here, Domingues da Silva attacks the long-standing consensus among leading historians of the region (such as Joseph Miller and John Thornton), according to which the expansion of the slave trade in the late eighteenth and nineteenth centuries pushed the slaving frontier continually further east into the continent’s far interior, with many slaves being prisoners of war provided by the expanding Lunda empire. Domingues da Silva refutes this claim mainly on the basis of two little (but increasingly) used quantitative sources: the lists of liberated Africans drawn up by the Mixed Commissions in Havana and Rio de Janeiro and the slave registers compiled by the Portuguese in Angola in 1855–1856. The ethnic origins mentioned in these documents, he argues, are trustworthy and show that the vast majority (72 percent) of slaves carried off in that period came from Kikongo-, Kimbundu-, and Umbundu-speaking societies much closer to the coast. As there were no large-scale wars in these regions, he continues, most slaves were not prisoners of war, but were enslaved due to internal conflicts, judicial proceedings (for unpaid debts, adultery, or witchcraft), and small-scale kidnapping (see also Chapter 6). According to Domingues da Silva, the particular mix of goods used for trading slaves and the traders’ price-sensitivity provide further evidence against the centrality of the Lunda expansion for the increase in the slave trade. They suggest that the main motivation for Africans to participate in the slave trade was economic, and not political. His view, hence, is one of many small-scale participants in the slave trade rather than a few big polities aspiring to accumulate political power (Chapters 5 and 6).
Although this argument is carefully constructed and well argued, some doubts remain. Quite surprisingly, the book is largely silent on the demographic conditions of the coastal societies in West Central Africa, from which the large majority of transatlantic slaves would have originated. Were these regions populous enough to sustain such a demographic hemorrhage over such a long period of time? Domingues da Silva’s discussion of the trade’s demographic impact on these societies is too brief and patchy for a robust answer. His assumption that Kimbundu and Umbundu populations even grew in the first half of the nineteenth century, which draws mostly on older demographic work by John Thornton, would need further substantiation. For instance, given that the Umbundu, according to his own calculations, lost 0.3 percent of their population annually to the transatlantic slave trade between 1831 and 1855, and that more than half of them were children, one might wonder whether this was “not a significant proportion” (p. 98). But above all, it would have been useful to situate such conclusions in the broader and controversial discussion about the trade’s demographic impact. Even those who have argued that the transatlantic slave trade did not lead to population decline for the continent as a whole (given that it presumably carried off only 0.1 percent of the total population annually, that women responsible for reproduction were only a minority, and that the trade also introduced new nutritious staples from the Americas) usually acknowledge that it did lead to tangible demographic losses in the trade’s hotspots. If not even the coastal societies of West Central Africa, with about 2 million people taken in less than a century, qualify for this sad honor, then it is difficult to imagine how others would.
A second doubt concerns the representativity of his quantitative sources. It remains unclear why Domingues da Silva does not include other sources, most notably the well-known registers of the Africans liberated by the Mixed Commissions in Freetown, to trace the precise origins of West Central African slaves. As it now stands, his argument is based on a sample of only 15,864 slaves (out of 2.8 million) that, moreover, is confined to the period between the 1830s and 1850s. Furthermore, one would like to know whether the ongoing research efforts linking the recorded names of liberated Africans to ethnic origins (and in which Domingues da Silva takes part) are prone to confirm his findings for West Central Africa.
These remarks, however, should not obfuscate that Domingues da Silva’s study is meticulously argued across the board and in many points convincing. Its claims are based on a series of little-used quantitative sources and in constant dialogue with the expanding secondary literature. The book manages to showcase how quantitative sources, if carefully selected, analyzed, and contextualized, can make a valuable contribution to our knowledge of “one of the largest and longest waves of coerced migration in history” (p. 15). Despite the manifold difficulties in using them, it is indeed “unfortunate”, as Domingues da Silva notes, that many historians of the slave trade have disregarded quantitative approaches because they would not adequately render African experiences or the social transformations wrought by the slave trade (pp. 8–10).
In conclusion, The Atlantic Slave Trade from West Central Africa, 1780–1867 not only offers new and controversial insights for scholars specialized in the transatlantic slave trade, it also touches upon a broad range of key issues in the historiography of the trade and its eventual abolition in the nineteenth century. Written in clear language and illustrated with many useful graphs, tables, maps, and images, the book would also serve teaching purposes very well.
 David Eltis / David Richardson, Atlas of the Transatlantic Slave Trade, New Haven 2010, pp. 18–19; 89–90.
 See, most notably, Joseph C. Miller, Way of Death. Merchant Capitalism and the Angolan Slave Trade, 1730–1830, London 1988; Luiz Felipe de Alencastro, O Trato dos Viventes. Formação do Brasil no Atlântico Sul, Séculos XVI e XVII, São Paulo 2000; José C. Curto, Enslaving Spirits. The Portuguese-Brazilian Alcohol Trade at Luanda and its Hinterland, c. 1550–1830, Leiden 2004; Roquinaldo Ferreira, Cross-Cultural Exchange in the Atlantic World. Angola and Brazil during the Era of the Slave Trade, Cambridge 2012 and Mariana Pinho Candido, An African Slaving Port and the Atlantic world. Benguela and its Hinterland, Cambridge 2013.
 See, for instance, John C. Caldwell / Thomas Schindlmayr, Historical Population Estimates. Unravelling the Consensus, in: Population and Development Review 28 (2002), pp. 183–204 and Patrick Manning, African Population, 1650–2000. Comparisons and Implications of New Estimates, in: Emmanuel Akyeampong et al. (eds.), Africa's Development in Historical Perspective, New York 2014, pp. 131–152.
 Richard Anderson et al., Using African Names to Identify the Origins of Captives in the Transatlantic Slave Trade. Crowd-Sourcing and the Registers of Liberated Africans, 1808–1862, in: History in Africa 40 (2013), pp. 165–191.