The Comparative Histories of Slavery in Brazil, Cuba, and the United States. By Laird W. Bergad (New York, Cambridge University Press, 2007) 314 pp. 80.00 cloth 22.99 paper; Slavery, Emancipation, and Freedom: Comparative Perspectives. By Stanley L. Engerman (Baton Rouge, Louisiana University Press, 2007) 114 pp. 25.00: