Why did Mexico City’s population grow so rapidly after 1940?

Mexico City’s rapid population growth after 1940 was primarily driven by massive domestic migration, as people moved from rural areas to the capital in search of economic opportunities and social mobility.12

Several key factors fueled this expansion:

• Industrialization: The city benefited significantly from the national policy of import-substitution industrialization (ISI), which encouraged and protected domestic manufacturing. By 1950, the capital accounted for nearly one-third of Mexico's manufacturing output, attracting a large workforce.1
• Infrastructure and Accessibility: The construction of the Pan-American Highway facilitated the arrival of thousands of migrants by bus, who were drawn to the city by the prospect of urban success.1
• Economic Centralization: As the political, economic, and industrial heart of the country, Mexico City offered a perceived potential for advancement that was unavailable in many provincial regions.12

While the population grew more than 12-fold between 1940 and 2000, this rapid urbanization also led to significant challenges, including the development of sprawling shantytowns and overcrowded tenements as the city struggled to accommodate the influx of new residents.1