Lázaro Cárdenas served from 1934 to 1940 and is one of the most important presidents of the twentieth century. He is best known for the 1938 oil expropriation, land reform, labor support, and receiving Spanish Republican exiles.

For citizenship exams, Cárdenas is essential. Connect him with oil nationalization, PEMEX, agrarian reform, and the social legacy of the Revolution.