Why did Mexico City grow into such a large metropolitan area?

Mexico City’s evolution into a massive metropolitan area is rooted in its long-standing role as a central hub for politics, religion, and trade, dating back to its origins as the Aztec capital of Tenochtitlán. Its highland location in the Valley of Mexico served as a natural crossroads for trade routes, which eventually formed the core of the nation's transportation system.1

Several key factors fueled its rapid expansion:

• Centralism: As the seat of government and a financial hub, the city consistently attracted people from provincial areas seeking employment, safety, and access to essential services like schools and hospitals.21
• Industrialization: During the late 19th century and throughout the 20th century, the city became the primary site for industrial growth. Policies such as import-substitution industrialization (ISI) further concentrated manufacturing output in the capital, drawing thousands of rural migrants.34
• Infrastructure and Investment: Government-led public works, such as the expansion of drainage systems and transportation networks, supported a growing population.35
• Migration: Waves of domestic migration, particularly in the mid-20th century, caused the population to skyrocket from roughly 3 million in 1950 to over 23 million by 2026.24