With all the attention about the 1940 U. S. Census returns that are now available, another census that many people will be interesting in checking is that of the nation of Mexico for 1930. The United States and Mexico are neighbors and many individuals will have ancestors who came from Mexico after 1930 or relatives from Canada or U. S. living in Mexico in 1930. So this census will be very valuable to track back some family lineage.
On the FamilySearch.org site, this free database of Mexico's 1930 Census is available to search. This census done in 1930 was the fifth census taken in the country since 1895. The United States only had four censuses since 1895 to 1930 in comparison. The one done in 1930 in Mexico was on May 15th. Unfortunately, as in any census count, there can be under reporting of people and households. It is estimated that about 78% of people were counted in the 1930 Mexico Census. That does leave many people not counted. It was estimated that there were over 16.5 million people in Mexico in 1930. Of that figure about 12.8 million were on the census records. Also with any census the information was provided by someone in the household, so there were mistakes in names, ages, etc.
The type of questions asked included the full name, age, listing who was the head of the household, birthplace for each person, their martial status, their religion, if they were married and how, the street address, each person's occupation and their nationality. One of the interesting questions dealt with where a person was married. It was asked if they were married in a civil ceremony or in the Catholic Church. That information could assist in locating marriage records.
The census locations are the numerous Mexican states such as Chihuahua, Yucatan, Baja California, Campeche, Chiapas, Coahulia, Colima, Durango, Guanajuato and many others. In the search box, place the surname and given names. Even if the spelling is a little different than what you have to search, a full selection of similar names will appear. Check the date of birth, birth place and residence in 1930 to see if you have a possibility.
Click on the one you want to view. There will appear a summary of the information, names, dates, occupations, etc in English. You can then view the actual Mexican census, but remember, it will be in Spanish. Even less traditional surnames of residents such as 'Smith' are shown. In the case of Smith there were 353 records and 167 Johnson individuals. It would count any resident in the country in May 1930, no matter were they originally came from. This just might be the place to search for a relative you could not find in the U. S. 1930 census.