David Eltis, Stanley L. Engerman, Seymour Drescher, and David Richardson, eds., The Cambridge world history of slavery: volume 4, AD 1804–AD 2016 (Cambridge: Cambridge University Press, 2017. Pp. xviii+705. 9 figs. 3 maps. 16 tabs. ISBN 9780521840669 Hbk. £129/$150)