When you trace the lines of descent of an ancestor through multiple generations, be prepared to observe the evolution of the family's surname. In the case of Johanna Falvey, American immigrant from County Kerry, Ireland, to Chicopee, Massachusetts, that is indeed what became of her married name.
With Johanna's 1875 marriage in Chicopee, the local registrar chose to record her husband's name as O'Reiley. True, we've already learned from subsequent census records that Johanna could neither read nor write, and it's almost certain that her husband-to-be, an Irish immigrant laborer, could do no more, so it's unlikely that either of them would speak up to correct a spelling "error."
This, however, was an era in which the spelling of surnames was far more in the control of the record keepers than the information givers, so I was quite prepared to see the surname morph, at least to the "common" spelling variation used at the time.
That was, indeed, what happened, come time for the 1880 census, where we found Johanna and her young son Frank listed with the more usual spelling as O'Reilly.
If I hadn't noticed any examples of the next aberration in my previous wanderings through the various Sullivan lines connected with this extended family, I might not have been prepared for the next variation in Johanna's married name. Searching online for any sign of the roots of these extended families, I had noticed the Irish vacillating between names with the "O" prefix and the same surname, minus the "O." I'd see Sullivan as the mother's maiden name in one baptismal record, and a couple years later in the same County Kerry parish, encounter everything the same, except now that same mom had become an O'Sullivan. Methinks the Irish see that "O" prefix quite differently than their Irish-American descendants do.
My first clue that this might be the case for our Johanna was in viewing her brother's obituary. Mark Falvey had died in 1912, long after his sister Bridget, but quite a few years before Johanna's passing. Thus, we have a record of Johanna's mention in Mark's obituary.
Clue: the "O" was missing.
Though Mark's funeral notice included his nephew Frank "Reilly" as one of the pallbearers, his actual obituary also reported Frank's mother's name in an entirely different rendition: as "Mrs. Patrick Riley." Indeed she was, albeit merely phonetically—though she wouldn't have known any differently.
At that point, there were no further entries that could be found in census records for Johanna. Her obituary in the December 15, 1927, edition of the Springfield Republican was perfunctory, stating the date of her death, her address, and details on the funeral and burial. The address given for the late Mrs. Riley agreed with the record we had found in the 1920 census, ruling out any possibility—a rather likely one, given the common surname—that it was announcing the passing of another woman by the same name.
Though the sole announcement of her passing listed no survivors, we already know that Johanna had a son. What had become of him? It was once again because we had traced the evolution of that family's surname that I could locate any record of Frank, who himself had a paper trail strewn with variations on his given name as well as his surname.
As it turned out, to insure I followed the trail of the right Frank Riley, there was another constant to guide my path: Frank's occupation. Frank Riley was apparently a lifelong employee of the postal service, so every time I found a document with that very common name, I checked to see where that Frank Riley worked. Following the trail of Frank Riley, postal clerk, I could piece together the story of his own life, as well.
Though Frank remained single, living at home with his mother through the 1920 census, after her passing, Frank did get married. One simple photo of their headstone at Find A Grave told almost the whole story, listing Johanna Riley's dates, followed by those for "Frank P." and then "wife Helen." Frank's date of death led me to his own obituary in 1941, which, in its one paragraph, provided not much more information than I had gleaned in his mother's notice and through the other records I found concerning him.
One item I noticed missing from that entry answered my final question: did he have descendants? If Frank Riley and Helen Shea Riley had any children, they did not survive him, for Helen was the only family member listed in Frank's obituary.
Despite the wild ride to persevere in tracing this Falvey line of descent through its various name permutations, in the space of one additional generation, that genetic signature disappeared from the ranks of future generations.