Two tropical commodities—coffee and sugar—dominated Latin American export economies in the nineteenth and early twentieth centuries. When Sugar Ruled: Economy and Society in Northwestern Argentina, Tucumán, 1876–1916 presents a distinctive case that does not quite fit into the pattern of many Latin American sugar economies. During the last quarter of the nineteenth century, the province of Tucumán emerged as Argentina’s main sugar producer, its industry catering almost exclusively to the needs...