William A. DePalo, Jr., presents the first English-language study of the Mexican national army from its genesis in 1822 to mid-century, when the independence-era protagonist faded from the national scene. The author gives substantive treatment to the various military reform programs undertaken to provide Mexico with a proficient and affordable armed force. To measure institutional proficiency, DePalo renders detailed analyses of the army's performance in answering the external challenges to Mexican territorial integrity posed in turn by Spain, Texas, France, and the United States. Also scrutinized are the endless peasant disturbances, Indian hostilities, and military uprisings that sapped army resources and detracted from its national security role. DePalo's penetrating analyses and succinct conclusions clearly explain how the regionalization and politicization of the military retarded the nation's political, social, and economic development and contributed to the loss of nearly one-half of Mexico's national territory.