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  • Writer's pictureJulie Wilmot

Estimating Dates

Julie A. Wilmot

Genealogists often use dates of marriage and/or birthdates of children to estimate an ancestor’s date of birth. A male ancestor who was married in 1830 and had children in 1831, 1833, and 1836, for example, may have been born circa 1805. It’s a reasonable estimation, but it may be wrong.

Recently, a client sent me a link to view a family tree on There was nothing on the surface that seemed incorrect; no glaringly obvious issues, like children born when the mother was ten, marriages occurring after death dates, etc. Still, I chose to recreate her work, given that she cited other trees as a source.

One of her ancestors fathered a child in 1888, so she had estimated his date of birth as circa 1865. She located a birth record for a man with his name who was born in 1863, and assumed it was correct.

I chose to locate the marriage record for this particular ancestor in hopes of verifying his parents and date of birth. After searching several records, I located his marriage, which occurred in 1886. The record noted that, at the time of his marriage, he was forty-two, and named his parents as two different individuals than the “parents” identified in the tree provided to me.

Once I had this information, I was able to determine he was born in 1844, nearly twenty years before my client’s estimate. I easily located the correct birth record and managed to continue tracing his line back several generations.

Why does this matter?

For several reasons, which I will elaborate on here. First, she had identified the wrong ancestors in her family tree. Yes, the people she had identified were relatives, but they weren’t in her direct line. Second, if the tree was public (thankfully it wasn’t,) she could have propagated incorrect information. Third, given her citation of other family trees on, she was the victim of the propagation of “bad” information.

The moral of the story is simple: verify, verify, verify. Marriages and other life events can provide us with estimates of dates of birth, but those estimates need to be proven before they are accepted. If we don’t locate evidence to support our estimations, we run the risk of wasting hours of research on ancestors who aren’t even ours.


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