For 50 years, Carlos Fuentes (1928-2012) was one of the leading literary and political figures of the Spanish-speaking world. A giant of Latin America's literary boom of the 1960s and '70s, his novels, including the classics Terra Nostra, The Death of Artemio Cruz and The Old Gringo, are passionate explorations of the history and identity of the Latin American nations, and of their contentious relationship with the superpower to the north. The son of a Mexican diplomat, Fuentes spent much of his childhood in Washington, D.C., returning every summer to his grandmother's home in...