I finished as much of my tree as I could without primary research, and the Irish connection seems to be about it. My great-great-grandmother (Hughes) was from Dundalk, in Louth County, Ireland. I can't find information beyond that, though apparently much (most?) of the physical data was destroyed. The Louth County tartan is one I could see myself wearing.

The coincidental part was when I started working on my wife's side of the family. Her g-g-g-grandfather had always claimed to be the son of Robert E. Lee, whose ancestry gets traced back to King Robert II of Scotland!

Definitely an interesting twist to my research.