Strategies for Census Research, 1850-1940 3

The U.S. federal census population schedules are among the most heavily used record groups utilized by genealogists. Beginning in 1850, they list the names and other information for every individual enumerated in the U.S. This provides a way for genealogists to track and identify individuals and their family groups. Here are a few strategies, tips and resources to help you use those census records to their full potential.


  • Track your ancestor through every census taken during his or her lifetime.
  • Transcribe 15-20 families on either side of the family you are interested in. Yes, it’s tedious and time consuming but you will be amazed at the tidbits of potentially important information you will find. Plus, it’s much easier to refer back to a complete transcription at a future date when you’ve hit a brick wall and you’re reviewing your previous work.
  • Approximate the marriage date for a couple based on the year of birth of the oldest child compared to the first year the couple appears together in a census. If you are unable to find the couple in a census prior to the birth of the oldest child, estimate by adding a couple of years to that child’s age to come up with an approximate marriage year. Also keep in mind the questions asked in:
    • 1850-1890: whether an individual was married within the year.
    • 1900: the number of years an individual was married.
    • 1920: the number of years in present marriage.
    • 1930: the age of first marriage.
    • 1940: women who currently were married or had ever been married were asked if they had been married more than once.

Use all of these clues to narrow the date range for a marriage.

  • Estimate a date of death range according to when an individual disappeared from the census. Use other resources like state census, tax lists, and city directories to narrow the date range.
  • Identify immigrant ancestors.
    • In 1870 males over 21 years of age were asked if they were U.S. citizens.
    • Prior to 1900 you can estimate the year of immigration for a couple by looking at the birthplaces of the children in the household.
    • From 1900-1930 immigrants were asked their year of immigration. Also a person’s naturalization status is listed. The 1920 census lists the year of naturalization.
  • Real estate inquiries were made in most censuses.  From 1850-1870 the value of real estate is listed. For census years 1890-1940 people were asked if they owned or rented their home. In 1930 and 1940 they were also asked the value of their home (if owned). If your ancestor owned their home, you will want to investigate deed and other property records.
  • Military service was listed in only a few censuses. The 1890 and 1910 enumerations inquired about Civil War service. 1930 inquired about military service during a war or expedition. Positive responses to any of these questions should prompt you to look for military records or pensions.

Other Tips

  • Stepchildren are not always identified as such. This applies to the enumerations beginning in 1880 where the relationship of each individual to the head of household is listed.
  • Individuals listed as boarders might be relatives.
  • Families living nearby may also be related or associated with your ancestor in a previous locality.
  • With the exception of the 1940 census, the informant is unknown. Always keep this in mind when evaluating the information and evidence in a census record.

Hopefully these strategies and tips will help you fully utilize census records when researching your ancestors.

Census Resources:

Clues in Census Records, 1850-1940 

Census Enumerator Instructions 

Census Resources and Links 

Hinckley, Kathleen W. Your Guide to the Federal Census for genealogists, researchers, and family historians. Cincinnati: Betterway Books, 2002.



Michelle Goodrum

About Michelle Goodrum

Writer, family historian, and researcher Michelle Roos Goodrum has been researching her family for over 20 years. Being the caretaker of over 135 years of her family’s papers and photographs, Michelle enjoys piecing her ancestors’ stories together. Michelle is also a Teaching Assistant for Boston University's Genealogical Research Program. Follow Michelle on her blog The Turning of Generations ( ) Michelle is the author of IDG’s monthly column, Timeless Territories.

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3 thoughts on “Strategies for Census Research, 1850-1940

  • Tonya Ferguson

    I’m new to genealogy. Is it possible for the same family to show up in early census records (1790) in adjacent counties? They were farmers.

    • Michelle Goodrum
      Michelle Goodrum Post author

      Hi Tonya,
      People did occasionally get double counted. It would be a challenge to determine in the pre 1850 censuses but not impossible.

  • Jade

    The 1910 U. S. Census questions also include number of years married, plus (of women) number of children borne and living, just like the 1910 enumeration. Oddly, on-line extracts do not include this data as done for the 1900 questions.