When searching for ancestors in the census, or other records, it is handy to have a probable birth year for the ancestor.  That way, when searching for John Smith, one can narrow down the time frame for possible hits.  However, have you ever discovered that birth dates can change from one census record to another?

I have been trying to find an ancestor in the 1900 census.  I have “M” in 1850 at 22 years of age.  In 1860, “Matilda” is 31 years.  In 1870, “Matilda” is 37, and in 1880 “M” is 48.  I have found “Mat” in 1910 at 75 years of age.  When “Martha” died in 1911, her death certificate lists her as being “86 78” years of age at her death.

So, what happened?  It could be that the census taker talked with someone differently from her, and her age was given as what that someone “thought” was correct.  Or, it could be that she did not really know her exact age, so she guessed.

In 1850 she was living with her brother and his wife (both she and her husband were residing there).  In 1860, she was living with her husband and her niece.  By 1870, she was living with her husband and a few younger nieces and nephews.  And, again in 1880, nieces and nephews were in the same household.  By 1910, she was living in a “Home for the Aged and Infirm.”  And, someone at the “home” was the informant on the death certificate.  If M/Matilda/Mat/Martha was not the informant to the census taker, that would explain the differences in her ages!  Especially for the aging of 11 years from 1910 to 1911!