Between 1920 and 1921, during the Revolution, people began migrating to Mexico CIty in order to escape the violence occurring in other parts of Mexico. This Revolution drove approximately 108,000 people from the provinces into the Capital. Since that time, Mexico City has doubled in size about every 15 years.
After the Revolution, the next wave of migrants moved to Mexico City in the 1950's and 1960's. This was primarily due to the economic policy at the time (import substitution) which was based on the growth of the internal market. They migrated there because that is where most industries were started and most jobs created. In contrast to later migrants, most of these migrants brought their families with them and moved to shantytowns. There, they formed neighborhood organizations that petitoned the government for materials to build houses, put in plumbing, and bring in electricity along with other amenities.
In the 1960's approximately 50% of the population of Mexico lived in rural areas but because of constant migration (mostly job seekers), that ratio has fallen to 20%. The primary states that have significantly contributed to the Capital's population include Michoacan, Puebla, Guerrero, Jalisco, Nuevo Leon, Hidaldo and Guanajuato. Between 1980 and 1990, 20% of the people immigrating to Mexico City were from Argentina, Brazil, Cuba, Spain, France, Italy and Japan.
Now, in 1997, about one third of the residents in Mexico city are migrants. Mexico City's population density is now competing with Tokyo and New York with 1,000 poor rural immigrants arriving everyday. Of the 20 million people living in Mexico City, 60% of the inhabitants were born there and 40% have migrated there. Even though Mexico City is vastly different from the pueblos of the migrants, most do not see it as the urban monster other sources claim it to be. Many migrants are hopeful about what the city offers--jobs, schools, cheap food, affordable transportation, and modern health care.