The more I look at Bishop Ussher's profile, the more I think he probably qualifies as a notable.
He's in several different Who's Who compilations for being a Bishop of the Reformed Episcopal Church in Canada, but he was also an M.D. and participated in the U.S. Civil War. (He also has a very brief Wikipedia page.)
He was also born in Dublin, so if he's a notable, he's also an Irish notable.
There's no sticker for the Reformed Episcopal Church, and I wasn't sure what other categories he should have.
I'm open to any and all suggestions.