Throughout each chapter, Sánchez undermines earlier anthropological arguments that Mexican communities, whether in Mexico or the United States, remained traditional or static in the early 20th century. Mexicans did not abandon their traditional practices altogether, but they adapted these practices and community-held values to reflect the rapid social and economic changes occurring around them. This process began in Mexico at the end of the 19th century, when the Mexican government, under the control of dictator Porfirio Díaz, pursued a policy of intense industrialization to modernize Mexico as a nation. Although Sánchez acknowledges that more remote regions of Mexico were impacted differently, he chooses to focus on the northern states and central plateau, where the majority of those who immigrated to the United States originated. The areas closest to the border with Texas were the first to experience industrialization, but the expansion of the railways connected communities deeper in the Mexican interior to urban centers in the northern states, and to Mexico City.

The industrialization of a previously rural society yields several predictable patterns, including the restructuring of traditional economies and an increase in geographic mobility. The opening chapters of Becoming Mexican American demonstrate the myriad of social changes brought on by evolving economic factors in Mexican villages, but similar adaptations also took place among the Mexican immigrant community of Los Angeles.