By 1821, a decade of bloody warfare had fragmented the viceroyalty of New Spain, divided the population into hostile factions of patriots and royalists, and intensified old hatreds among peninsular, or European-born, Spaniards (gachupines), American-born criollos, the complex racially mixed groups, and the indigenous population. In many regions, the native villagers were angry, resentful, and politically mobilized. The war had taught different segments of the population that mobilization and the effective use of political action—even violence—could address their political demands, their interminable grievances concerning landholding, and their chronic disputes over taxation.
These campesino insurgent and guerrilla fighters, many of whom knew little Spanish, fought tenaciously and often successfully for different factions and regions. Although some sought to escape combat and brutal suppression by fleeing into rugged mountains or posing as neutral noncombatants, guerrilla warfare, endemic banditry, and pervasive violence changed the lives of ordinary people.
In the cities, large floating populations of vagabonds, gamblers, and petty criminals frequented cockfights, bullfights, and other popular entertainments; loitering in parks and public markets, they made the night extremely dangerous for respectable urban residents. Nevertheless, even as indigenous and mestizo people suffered from the dislocations of war, arbitrary conscription, heavy taxation, and narrow paternalism, some also developed feelings of pride and empowerment that would find new expression in the post-independence decades.
By the outbreak of the war with the United States twenty-five years later, Mexico was ill-equipped and unprepared to defend its territory. Its economy was in ruins, its army lacked modern weapons and training, and many of its citizens were unwilling to engage in the defense of a nation that they did not fully comprehend. Others rose to lead the republic in its heroic, but impossible, defense.