Mora-Torres argues that the years between the establishment of the U.S.-Mexico boundary in 1848 and the outbreak of the Mexican Revolution in 1910 constitute a critical period in Mexican history. The processes of state-building, emergent capitalism, and growing linkages to the United States transformed localities and identities and shaped class formations and struggles in Nuevo León. Monterrey emerged as the leading industrial center and home of the most powerful business elite, while the countryside deteriorated economically, politically, and demographically. By 1910, Mora-Torres concludes, the border states had already assumed much of their modern character: an advanced capitalist economy, some of Mexico's most powerful business groups, and a labor market dependent on massive migrations from central Mexico.