Thomas Farrell Elderly OvalI was stumped.  No one in the family knew when and where Thomas Francis Farrell married.   It may have been in Ireland (his place of birth), England (his last known residence before immigration to the U.S.), or in the United States.

I found him in the 1900 U.S. census.  That record revealed he had been married 38 years, and that he immigrated in 1857.  His wife, Sarah, had immigrated in 1858.  I did the math and determined they had been married in the U.S. about 1862.  Tracing back through the censuses, in 1860 he had been living in Boston, Massachusetts.

Armed with a possible year and place, I searched the marriage records for Boston, and found his marriage record in 1862!  Having the information from the census was the key to finding the record.

The census is one of the best tools we have for research.  It is like a roadmap.  It is not THE destination, however.  Census records are only evidence of a person living in a particular locality. All other information found in the census needs to be verified through more original sources.  So, use it like a a road map to know where to look to find their records.

Also, a caution is needed:  The information found in the census may not be accurate because the informant might have been a neighbor who didn’t know the family very well and just guessed, or he or she may have been a family member that didn’t know or intentionally gave the wrong answer.

With that in mind, let’s look at what makes the census so valuable.  United States federal censuses were taken beginning in 1790 and thereafter every ten years.  Currently, we have access to the censuses from 1790 until 1930, but the 1890 was damaged and mostly destroyed.   (Some states had censuses as well, but we’ll save that discussion for another day.)

U.S. Censuses became more detailed over time:

  • 1790 to 1840 – only the head of household is named, but hatch marks reveal various age brackets within the home.  Don’t give up on these censuses.  They are valuable because you may be able to place the family members within their age brackets, verifying you have the right family.    Not everyone in the household may be related, however, as some may be boarders or workers.
  • 1850 – first time everyone is named, but no relationships are stated, also lists age, sex, color, occupation, value of real estate, birth place (usually the state or country), married within the year, attended school within the year, cannot read or write
  • 1860 – similar to 1850, but includes value of personal property
  • 1870 – similar to 1850, but also includes father foreign born, mother foreign born, month born in the year, month married in the year, eligible to vote
  • 1880 – first time relationships to the head of household are listed, first time listing for father’s place of birth, mother’s place of birth, marital status, month of birth if born in the census year
  • 1890 – mostly destroyed, surviving schedules include Civil War Union veterans and widows of veterans
  • 1900 – address, month and year of birth, place of birth, year of immigration, if naturalized, number of years married, mother of how many children and how many still living
  • 1910 – similar to 1900
  • 1920 – similar to 1900, reveals immigration year and naturalization year
  • 1930 – similar to 1900, shows whether a veteran or not

You should try to find your ancestor in all possible censuses during his life, as each may reveal different valuable clues.  When you find your family on a census page, look closely at the neighbors on surrounding pages.  Some may be relatives you have not as yet discovered.  Then, study the actual entry for the clues you find there.  If you find a record for:

  • Number of years married = look for a marriage record
  • If place of birth is a foreign country = look for an immigration record
  • Year of immigration = look for a passenger list.  If subject was the age of a child at immigration, search for his parents on the passenger list as well.
  • Naturalized citizen = look for a naturalization record
  • Mother of x number of children, number living = search for missing children
  • Occupation = valuable in connecting a man with a common name over time, also there may be school records, trade associations, etc.
  • Owns home = search land records
  • Cannot read or write = documents may be signed by their mark or “X.”
  • Older person with different name in the household = may be with wife’s parent

Censuses can be found online at and HeritageQuestOnline. is subscription based, but you can sign up for a free trial period.  Heritage Quest is a subscription site, but many libraries allow subscription access to their patrons from home.  So, check your local library to see if you can access it that way.  You may also visit your local branch of the Family History library and view the online censuses there.

So, go check out the census, trace them back in time as far as you can, then use the information as your map to see what you can find out about your family!

How has the census helped you in your family searching?