In Mala Sangre: Religion and Race in Colonial Latin America, Stuart Schwartz traces the origin of racial and ethnic classifications. Here, Prof. Schwartz argues that such hierarchy and division may not have originated in the 19th century (with the work of Linnaes and the dissemination of Social Darwinism), but rather, much earlier and as the result of Iberian settlement and exchange in the Americas. Instructors and students of the early modern Atlantic world will find this a helpful explanation of the introduction, expansion, and navigation of the casta system.