Today, March 18th, is a date that many Mexicans associate with an important moment in our history, but what is actually celebrated on March 18th? Well, it commemorates one of the most decisive moments for the country: the Oil Expropriation of 1938.

It all began with a rather intense labor conflict. Oil workers were tired of poor working conditions and unfair wages, so they filed their demands. The Federal Conciliation and Arbitration Board sided with them, but the foreign companies controlling the industry outright refused to comply. That was the trigger.

President Lázaro Cárdenas del Río did not stand idly by. On March 18, 1938, he issued a decree that changed everything: he nationalized the oil industry. In one stroke, 17 foreign companies lost control of their operations. We are talking about refineries, pipelines, distribution stations, vessels, all the infrastructure. Among them was the Mexican Company of Oil El Águila, linked to Royal Dutch Shell, as well as other oil and transportation companies.

The justification was clear: to defend workers and ensure that Mexico’s natural resources remained in Mexican hands. Months later, on June 7, 1938, Petróleos Mexicanos was born, the state-owned company responsible to this day for exploring, exploiting, refining, and marketing oil.

Today, nearly 90 years later, oil activity remains crucial to the national economy. Production is mainly concentrated in nine states, with Campeche, Tabasco, and Veracruz being the primary ones. In fact, about 90% of the oil is extracted from just 18 municipalities located in these three states. What’s interesting is that what is celebrated on March 18th goes beyond the numbers: it’s a symbol of energy sovereignty, a reminder that Mexico took control of its own resources. Cárdenas’s decision continues to be part of our national identity.