McCann has written a fascinating social history of the propagation of maize throughout sub-Saharan Africa since it was first brought there from the New World, probably in the cargo of a slave ship, around 1500. He chronicles the ways in which maize has adapted itself to African conditions, slowly becoming a major African food staple. Since World War II, in fact, the emergence of hybrid maize has resulted in a sharp rise in maize cultivation in Africa, displacing traditional indigenous crops. McCann celebrates the ingenuity of African farmers as they adapted the crop to local customs and climactic conditions, but he argues that the policy world has largely ignored the socioeconomic and environmental implications of the emergence of maize as a staple. In the book's most fascinating chapter, he convincingly links a major malaria epidemic in the highlands of Ethiopia in 1998 to the widespread adoption of maize in the area over the preceding decade.