We have another match!
DNA testing rarely solves a family mystery all at once. More often, it reveals patterns over time. A while back, I wrote about the results of my brother’s Y-DNA test, which I covered in more detail in a previous article. Y-DNA testing aids in uncovering and confirming a man’s direct paternal lineage by connecting him with others who descend from a shared patrilineal ancestor.
I asked my brother to take a Y-DNA test in an attempt to determine which Long Island Hendrickson family our Uriah Hendrickson (1750–1839) descends from. While I had my suspicions, to my surprise, our closest match was to descendants of Gershom W. Henderson (1801–1857) of Whitesboro, Oneida County, New York.
Our new match is with a descendant of Major John Hendrickson from Hempstead, from whom we are supposedly descended, according to Andrew J. Provost, author of The Hendrickson Family of Long Island. Documentary evidence, including probate and burial records, contradicts that theory, and so far, the DNA evidence supports that.
What the Results Tell Us
The results do not specify the exact relationship, but they confirm that we share a common paternal ancestor with descendants of Major John Hendrickson (1733–1815). Just like the other Hendrickson matches, the genetic distance is two. The other Hendrickson matches were to descendants of John Hendrickson (1781–1855) and Rosetta Thurston of Foster’s Meadow and Brooklyn, and to an unknown Hendrickson whose identity remains uncertain.
While we don’t descend from Major John Hendrickson, the additional match strengthens the case that Uriah Hendrickson, John Hendrickson, and Major John Hendrickson all share a common Hendrickson ancestor, likely going back to the 1600s or earlier.
If my suspicions are correct, and we descend from Thomas Hendrickson (1704–1776) of Oyster Bay, the current DNA evidence could still support that scenario. In Andrew J. Provost’s reconstruction of the family, both Thomas Hendrickson and Major John Hendrickson descend from Harmon Hendrickson, born about 1612 in Holland. Additional testing is needed to see if my theory still holds water.
And we can’t forget that we have an exact match to descendants of Gershom W. Henderson, which suggests that he and Uriah were more closely related. The trick is determining exactly how Gershom W. Henderson fits into the picture. So far, I do not have any promising leads.
Future DNA Testing
The results could shift with additional testing. Upgrading my brother’s Y-DNA test to 111 markers or more may help refine how closely we match these lines and confirm whether the current pattern holds when more markers are compared.
Although we now have a clear genetic connection to both the Henderson and Hendrickson families, the exact nature of those relationships remains unresolved. Ongoing research and additional testing will be crucial in unraveling these familial mysteries.
The most useful comparison, however, could come from testing proven descendants of Thomas Hendrickson. That is the line that could most directly support or challenge the current theory. In practical terms, that would also likely require arranging and possibly funding targeted testing of those descendants.
For deeper insight into our paternal line, Big Y-700 testing would provide the most detailed picture of how these branches split. At roughly $340, it is a significant expense for my brother’s test alone. If anyone would like to contribute toward future testing, I would greatly appreciate the help.
For now, the evidence continues to point toward a deeper connection between these Hendrickson and Henderson lines. Each new match adds another piece to the puzzle, even if the full picture remains just out of reach. With additional targeted testing, we may finally be able to determine where these families converge.