Found another one!
I was doing a pass through newspaper archives this weekend, and found another article about Annie Einhorn. Annie was the sister of my great-great grandmother Sarah (Einhorn) Allweiss, who died under tragic circumstances weeks after arriving in New York.
Over at the Library of Congress's website "Chronicling America" was the most extensive -- and painful -- article on her death that I've found yet. (And over a century before things "go viral", her story was in newspapers literally around the world.)
That prompted me to revisit her death certificate. Father's name, Noah, mother Regina -- although on Sarah's second marriage, she gave her mother's name as Tillie Prise. I decided to go over to FamilySearch and see once more if I could find any other siblings in New York; in particular, I tried a variant strategy on looking in the marriage records.
In particular, I looked for NYC marriages for someone named Einhorn whose father's first name began with N and whose mother's first name began with R (no results) or T (one result).
That one result was for Max Einhoren, son of Nathin Einhoren and Toba Preis, marrying Fanny Cohn, daughter of Barny Cohn andTohbe Ferziger, on 20 Dec 1898. That's a pretty good match.
So I tentatively entered those new names into my Ancestry.com tree, and waited for the waving green leaf to appear. Sure enough, there were likely census matches in 1905, 1910, etc. These gave me the names of children: Nathan (b. 1904), Rose (b. 1908), and Harold (b. 1913). The family moved to Chicago. (I still haven't fleshed out all the intermediate steps, nor have I started working on the children's lives yet. I want to capture this moment while the details are fresh in my memory.)
I went to jewishdata.com and searched for Einhorn graves in Chicago. I recalled having seen some earlier, but until now I had no reason to pursue a Chicago connection. Sure enough, there are graves there for Max and Fannie. Max's stone gives his Hebrew name as Michel b. Noach ha-Kohen -- and I knew from Sarah's gravestone that her father was Noach ha-Kohen. Fannie's stone gives her Hebrew name as Frumet b. Dov Ber -- a good match for Barney.
This evidence seems strong and I'm convinced that Max was my great-great-grand-uncle. The next step is to start working on descendancy research and see if I can find any cousins on that branch.