Census 101

Using the Census to Build Your Family Tree
It's difficult to state with any certainty which data source is the most important for genealogists. Vital Records (birth, marriage, and death records) and Passenger Lists are certainly critical, but few sources are as detailed and as periodic as government census schedules.

Whether you'll be using the U.S. Federal Census or those of another country, state, or locality — census schedules provide a means to track members of a family group over time. This allows you to build a detailed timetable and, in some cases, obtain clues about the lives of your ancestors that may not appear in any other source.

Stepping Backwards Through Time
As is often the case in family history research, you'll find it easiest to step backwards through time when researching one or more family members in the census. Since Federal privacy laws restrict the U.S. Census from being viewed for 72 years after the original census date, the 1930 Census is the most recent U.S. Census available for research. The 1940 Census schedules won't be released for public inspection until April 2012, so you've got plenty of time to become a census expert.

Getting Started
To begin, have an individual or family group in mind. It's always tempting to simply jump right in and start searching — especially when using the Internet. Careful planning, however, can save you hours of wasted effort. When preparing to conduct a search in the census, you should arm yourself with as much data as possible for the person or family you will be searching for.

• What was the real name of your ancestor?  ("Uncle Joe" might have been Patrick Lynch)
• What was the maiden name of your female ancestor?
• What were the names of siblings who may have been living with your ancestor?
• Where might you expect to find this family or individual living in 1930?
• Approximately how old would this person (or persons) be in 1930?

Once you have some of this basic information, you'll be ready to begin. The procedure for conducting your search is basically the same online or offline, the big difference being the time required to obtain results using microfilm vs. the Internet. Keep in mind, many libraries, regional archives, and family history centers have online access to the U.S. Census, so even if you don't have a subscription of your own, you can benefit from understanding how to best use your time conducting research.

EXAMPLE: Using the 1930 U.S. Census, we'll search for an Italian-American family living in the state of Connecticut. We know from other sources (headstone, obituary, death certificate, etc.) that Domenic Ditoto died in the early 1960s, but had lived in America for more than fifty years. Based on other family information, we expect to find Domenic living in the city of Waterbury which is in New Haven County. Having been born about 1884, we're expecting to find a 46-year old living with his wife (Anna) and at least a few children. Since our family information shows some of Domenic's children to be in their late teens, it's possible they have already moved away.

An initial online search using an exact name match in Connecticut turns up empty. So too does a Connecticut-wide search using a soundex match. Now what?

Consider the following census search strategies:
a. Remove first name from the equation, try using last name only in conjunction with city/state
b. Use last name only and approximate year of birth, include all states (just in case)
c. Search for spouse instead of head of household (use first name of head to narrow results)
d. Search for one or more children instead, using approximate year of birth

Continuing with our example from above, attempts using strategies a, b, and c failed to flush out our person (or family). Using the fourth strategy (d), however, we have some luck. In this case, we use the names of several children in an attempt to back into our desired results. Our first search was for a daughter named Louise, leaving the Last Name field empty. We specify Connecticut, New Haven county, and Waterbury township. An approximate year of birth further narrows results, but still yields too many for quick evaluation and none that seem to match the first name Louise.

The same process was repeated with several other children until, at last, success with the youngest daughter Rita. Using no surname, we simply look for any family in Waterbury, New Haven, Connecticut where a daughter born about 1923 was named Rita. There are several hundred records matching this query, but adding Father's Given Name as Domenic further narrows the field. And since genealogy also involves a little luck — the first result of this newly refined query was a Rita Ditots. Note how the last letter of the surname being incorrectly transcribed as an 's' instead of an 'o' kept this record hidden from view. In addition, the eldest daughter's first name was recorded as Louisa (the Italian given name), rather than as the Americanized name Louise.

Domenic Ditoto, the head of household, isn't visible on the partial page above because he was enumerated on the last line of the previous page. The record for his family, however, confirms a number of facts gleaned from other sources and also provides a number of new facts (for instance, his wife Anna shows a year of immigration to the United States as 1906 (likely from Italy) and that she was not yet an American citizen.

Conclusion
The example above shows how you need to be careful, patient, and creative when searching the census. The benefit of using the census over other sources is that you have the option of searching for an entire family group person by person and will likely find others as your reward.

Next Steps
After you have searched the 1930 Census, you should evaluate the information for the family group you have found and then step back ten years to the 1920 Census and keep stepping back through available census until can determine the arrival of your family origins in this country.

Tips for a Successful Search (Online or Offline)
Once you have indentifed a person you are trying to locate in the census, you should have as much information as you already know to help ensure an easy search. This is especially true for common names! If you're searching for a 'John Murphy' in the 1900 U.S. Census for New York City, you'd better know his occupation and approximate age if you want to narrow down the possible matches to your search.

Consider the following steps:
1. Determine which census years apply given birth/death dates for the person you're researching
2. Start with the most recent census available to you (eg: 1930 is better than 1920 or 1910)
3. Where possible, obtain detailed geographic information (eg: City, County, and State)
4. Consider possible variant spellings or misspellings (see soundex overview)
5. Determine approximate age and others who may be living in the same household

If you have comments or questions about the content of this Census 101 page,
please contact us at your convenience.