Mexican culture reflects the complexity of the country's history through the blending of pre-Hispanic civilizations and the culture of Spain, imparted during Spain's 300-year colonization of Mexico. Exogenous cultural elements mainly from the United States have been incorporated into Mexican culture. As was the case in most Latin American countries, when Mexico became an independent nation, it had to slowly create a national identity, being an ethnically diverse country in which, for the most part, the only connecting element amongst the newly independent inhabitants was Catholicism.The Porfirian era (el Porfiriato), in the last quarter of the nineteenth century and the first decade of the twentieth century, was marked by economic progress and peace. After four decades of civil unrest and war, Mexico saw the development of philosophy and the arts, promoted by President Díaz himself. Since that time, though accentuated during the Mexican Revolution, cultural identity had its foundation in the mestizaje, of which the indigenous (i.e. Amerindian) element was the core. In light of the various ethnicities that formed the Mexican people, José Vasconcelos in his publication La Raza Cósmica (The Cosmic Race) (1925) defined Mexico to be the melting pot of all races (thus extending the definition of the mestizo) not only biologically but culturally as well. This exalting of mestizaje was a revolutionary idea that sharply contrasted with the idea of a superior pure race prevalent in Europe at the time.