Census Records in Hispanic Research
Generally, both in the United States and Latin America, census records have a column to indicate the country of birth. Fortunately, the census records of Spain and Latin America (especially those of the colonial era) sometimes indicate a specific province or parish in the country where the ancestor was born. There are many exceptions, however, particularly in the U.S. federal census records from the Southwest, where frequent and close association with the various Mexican states created an atmosphere in which the census taker would record the name of the Mexican state in response to the census question regarding the state or country in which the person was born. Census records ought to be carefully consulted, therefore, even though they may not ordinarily yield anything more than the country of origin.\\
Later censuses in many countries, such as the all federal censuses in the United States from 1900 and later, also indicate whether or not the individual was a naturalized citizen, and how long he or she had been in the country. This information indicates the time period in which the person entered the country and whether or not there may be naturalization and citizenship records.
One researcher knew only that his ancestors, Bonifacio Torres and Josefa Rangel, lived in Arizona about the turn of the century. A search for them in the Soundex index for Arizona for the 1900 census resulted in finding the census page reproduced in the attached image. From this the researcher learned his ancestors' ages, the year they came to the United States, and that they lived in Florence, Arizona. From the census, the researcher deduced that Josefa Rangel had not been married when she came to this country. He then wrote the Catholic parish church in Florence, asking if there was a marriage record for Bonifacio Torres and Josefa Rangel before 1900. In response, he received a certificate that gave him a marriage date but nothing about their place of origin in Mexico. He then wrote a second letter asking for a verbatim copy of the marriage entry, as he should have done originally. He received a photocopy of the original marriage entry stating that Bonifacio Torres and his family were from Alamos, Sonora, Mexico, and that Josefa Rangel and her family were from Ures, Sonora, Mexico.