The 354 Sheridans, and the segment that finally pointed home

Bridget Sheridan is my great-great-grandmother. She was born in County Cavan circa 1828, crossed to Massachusetts sometime in the 1840s, married Patrick Caughlin at Chicopee on 7 November 1846, and died in 1897. Everything I have ever been certain of about where she came from sits in a single line on a marriage certificate: County Cavan. That is the whole of it — no parish, no townland, not a word naming her mother or father. The county I have never doubted, because that certificate is solid. It was the WHERE in Cavan could not get past for the longest time. This is the story of how I finally started to — and it did not go in a straight line.

When there are 354 of them, how do you start?

Here is the problem in one number. When I went looking for Bridget’s people in Griffith’s Valuation, I was staring at something like 354 Sheridan households scattered across Cavan. Sheridan is a Breifne name. It is a needle in a stack of identical needles.

I did not have a clever way through that. So I did the only thing I could think of: chase down every Bridget Sheridan I could find a birth or baptism for, and try to trace each one forward, hoping that if I could account for enough of them staying in Ireland, whoever was left over — vanishing around 1846 — might be mine.

The records fought me the whole way. The Catholic registers for the parishes I most needed begin too late; many do not start until the mid-1830s, after Bridget was already born, so her baptism simply is not in a book anywhere. And most of Cavan’s 1841 census — the one thing that might have placed her in a household as a girl — was destroyed. For whole stretches of the county I was not working with thin evidence; I was working with a hole where the record should be.

It kind of felt like swimming against a rip tide.

The Killeshandra lead I couldn’t confirm — or clear

One place kept surfacing: Killeshandra, up in the north-west. There is a Bridget Sheridan in the surviving scrap of the 1841 census there, Sheridan farms at Losset and Drumcoghill, even a member tree naming a William Sheridan of Drumcoghill Upper with a daughter Bridget born circa 1828 — exactly the year I wanted.

For a while I let myself feel like I had found her. Then I made myself ask why Killeshandra kept shouting, and it deflated the whole thing. Killeshandra shouts because it is one of the very few parts of Cavan where the 1841 census survives.

The record is not louder there because Bridget is likelier to be from there — it is louder because none of the other census returns even existed.

And the Bridget in that surviving scrap is a servant, living away from any family of her own, which tells me where a girl was working, not where she was born. And it can’t tell me where hundreds of other undocumented Bridgets were…

A record that survives is not the same as a record that’s right.

Then came the part that really stopped me. I could not rule the Killeshandra candidate out — but I slowly realised that not being able to rule her out was not the same as ruling her in.

I was trying to empty a room by counting the people I could see, with half the lights off. So I did something I do not do often. I set it down, closed the tabs, and walked away. After trying to run down all those Bridgets – I had to have a break.

Starting again, from the other end

When I came back, I came back from a completely different direction: I stopped looking at records and started looking at DNA matches — the ones shared with our eldest tested known relative on this line, the single living kit that carries 50% more of Bridget’s DNA than I do.

The first knot to untie is to untangle Bridget’s DNA from the Patrick/Bridget couple DNA. Bridget did not come down to us alone — she came paired with her husband, Patrick Caughlin. They are a married couple, and both of them are my ancestors. So when a stranger shares DNA with us “on the Irish side,” nothing on the surface says whether they are a Caughlin cousin or a Sheridan cousin. Every Sheridan clue is tangled up with a Patrick clue, and untangling them is the whole game.

Surname by surname

So I went hunting — and I did it the slow, slightly obsessive way. I worked through our MyHeritage matches surname by surname, opening people’s family trees and looking for the names I would expect on Bridget’s side: Sheridan first, then Reilly, Galligan, McCabe, and on down the list.

I want to be honest about what those trees are worth, somtetimes. Other people’s online trees are often wrong — copied mistakes, hopeful guesses, the same record stapled to the wrong person a hundred times over. I am 100% certain my tree has the same kinds of errors as it is a work in progress and a todo list at the same time.

I never treated those trees as evidence. I treated them as somewhere to start — a thread to pull — and then I took every promising match into the chromosome browser to see whether they actually shared the same stretch of DNA with us and with each other. That last part, matches triangulating on the same segment, is the thing a coincidence cannot fake.

 

• • Searching Sheridan surfaced a group triangulating on chromosome 9 whose trees were thick with Sheridan, Brady, Reilly and Lynch, rooting along the Cavan–Meath border around Ballyjamesduff, Mount Nugent and Oldcastle.

• • Searching Galligan led to a group on chromosome 5 — Galligan, Reilly and Sheridan — anchored by a match descending from a Galligan born in Corduff, in Crosserlough. (When I later went back to Griffith’s for Crosserlough, there was a Galligan renting a house directly from a Sheridan in the village of Kilnaleck)

• • Other surnames filled in more of the same neighbourhood: a chromosome 1 McEvoy/Galligan/Mulligan group, and a chromosome 13 Reilly/Sheridan group anchored by a Reilly family of Mullahoran — one member descending from a documented Rose Anna Sheridan.

Every one of these pointed at the same tight community in south Cavan — and pointedly not at Killeshandra. That was thrilling. It was also, I had to keep reminding myself, not proof. The trees had Sheridans near the matches, but not one of these groups had a documented Sheridan I could tie straight to Bridget. Every single one was still only a reasonable hypothesis. I had a glowing map of a neighbourhood and no address.

The surname that wasn’t Sheridan at all

The break, when it came, came from a name I was not chasing for Bridget’s sake. Running a Gaffney and a McCabe search turned up a new triangulated cluster on the p-arm of chromosome 3 — a match whose tree, an unusually well-documented one, carried Gaffney, Mulligan, McCabe and McGovern, and a cousin of hers carrying Loughlin of Cavan. At first I filed it as just another maternal cluster with Cavan surnames. It did not have a Sheridan in it anywhere.

And then I noticed who else was standing on that exact segment.

The cousin I already had

One of the people triangulating on that chromosome-3 segment was a second cousin of ours — a known one, whose descent I can trace line by line inside my own tree. That changed everything, because it let me run the segment backwards through people I could actually prove.

Here is the chain, and it is the most solid thing I have ever had above Bridget’s wall. The whole cluster is maternal — every member also shares DNA with two documented cousins on the maternal Caughlin side, so none of it is coming down the paternal line. That second cousin and our eldest tested relative both descend from James Caughlin — the only one of Patrick and Bridget’s children to leave descendants of his own. So the segment we share has to come down from James Caughlin and his wife: only two possible sources, Patrick’s line or Bridget’s, with the wife’s line as a third to rule out.

So I ruled them out. Patrick’s own Offaly line is excluded by DNA: three documented cousins from two descendant branches from that Coughlan/Offaly branch do not carry this chromosome-3 segment at all, so it cannot be reaching me through Patrick. His son James’ wife’s line is excluded by geography: she was of German stock, and every surname sitting on this segment — Gaffney, Mulligan, McCabe, McGovern, Loughlin — is unmistakably Cavan.

Strike out Patrick, strike out the German line, and there is one source left: Bridget Sheridan herself. After all those months, a piece of DNA I could finally point at and say that came down from her.

This one is interactive. Tap or click any chromosome bar — or any group in the list below it — to isolate that cluster and see what it rests on.