A few proven suggestions are offered which just might create a major breakdown in that ‘wall’.
Be organized. Review what you do have to date, recheck documents and other records even if they cover other individuals or different family branches. By just taking the time to organize your notes and information sheets as you review them could just spark a clue as to another name or location you had not checked so far.
Time Frames. Dates can be one main portion of your search to be messed up. All it takes is one record to mistakenly to have down the wrong date for a birth or marriage and that same date continues to be repeated. Plus our ancestors were known for changing their birth year to avoid any embarrassment. If your grandmother appears to have different birth dates, it could be her parents had married say in February 1898, she might not want it known as the first born child, her birth was only three months later. I have even found where the doctor who delivered a baby changed the birth month / year, just so later the child could enter school earlier. So always be ready to search other time frames for events; start moving that scale several years either way when trying to find that ancestor.
Siblings. Some of the most successful searches for one individual were due to searching for that person’s siblings. Especially helpful is if that sibling had an unusual given name. Now searching using sisters can be more difficult because of married names, but be willing to give that angle a try also. Some siblings could have been more accomplished or noteworthy, so possibly easier to locate.
Various Spellings. Oh — how given and surnames have changed over the decades. You have to be prepared to investigate numerous spellings for the same family branch. The further back you go in the family lineage the more likely the surname was spelled different.
Here is one example for the ‘Rue’ surname:
First written — 1840 — Routh
then 1850 — Ruthe
then 1860 — Rough
then 1870 — Rouch (and Rouche)
then 1880 — Rue
Within a span of forty years it went through five various spellings – the same family and their descendants.
If an ancestor was illiterate, when it came to the census taker coming around every ten years or a marriage record filled out, the recording clerk or census worker would just make their best attempted at the name’s spelling based on how the person pronounced it.
While doing your research try various spellings, it could pay off with finding a missing relative.
The main key to a baffling ancestor is to use as many diverse sources as possible — leave no ‘stone unturned’.