Key to the city: Yellow fever, medical knowledge and the control of the port of Veracruz in the nineteenth century

Veracruz was the single most important port of New Spain and independent Mexico, the land's link to Caribbean and the broader Atlantic world.  It was also notoriously unhealthful.  Foreigners who arrived at the port, natives of the Mexican highlands, and even many of the most prominent Veracruzanos sought to spend as little time within the city's walls as possible.  Situated in the narrow band of tropical lowlands along Mexico's gulf coast, Veracruz hosted endemic yellow fever, the most feared disease in the western hemisphere during the nineteenth century.  During the first half of the century, a period that witnessed Mexico's transition from colony to independence as well as its partition by conquest, the city was repeatedly contested by the armies of Spain, France, Mexico, and the United States.  This paper will examine how evolving medical understandings of yellow fever shaped military strategies of both the invaders and the defenders who sought to control this port city and so the key route to and from central Mexico.