Margaret Gallagher (Widow McDermott) might possibly have just passed him off as her Nephew....
Yes, I had originally assumed that being illegitimate and being Bridget's son, Bridget's maiden name was McDermott. That is why we couldn't find a birth registration for Thomas - because we were looking for the wrong surname. There are no other McDermott's connected to the family as far as I know. I have no bleep-bleep idea who "McDermott" was or where the name has come from. Thomas was registered as Keegan. Sometime between birth and 12 years old, he morphs into Thomas McDermott.My parents and all my many Irish aunts and uncles are now dead, but they talked long and hard about their Irish-ness. I've never heard the name Keegan before and I'm sure the family knew nothing about this. I have contacted parishes in Boyle, (where Bridget settled), Carrick, the Carrick History Society and the main library in Leitrim. They have all been incredibly helpful, but found nothing at all.