I have a new topic in the general area of "notables": Namesakes of the Dim Past, by which I mean once-notable people who were popular namesakes for children in past centuries, but whose names we no longer recognize as names of famous people.
For me, this started with Harriet Newell. A great-grandfather of mine had a sister with the given name (first and middle name) Harriet Newell, so I was on the lookout for hitherto unknown relatives named Newell. After running across an apparently unrelated family that named a daughter Harriet Newell, I Googled the name and found a Wikipedia article in which I learned that Harriet was a very young woman from Massachusetts who had died after going to India to be a missionary, and whose story had inspired many 19th-century American families to name their daughters Harriet Newell. I could stop looking for relatives named Newell, because it was clear where my devoutly religious ancestors had gotten this girl's name!
Now when I run across a family member with a middle name that sounds like a surname and isn't recognizable as the name of a family member (or a well-known notable like Benjamin Franklin or Jenny Lind), I search the Internet to see if the first and middle name represent a famous person of the dim past. In addition to Harriet, I've found family members who apparently were named for three popular Christian ministers of yore: Edward Payson, Lorenzo Dow, and John DeBaun. (Of these, Payson and Dow were both popular as namesakes.)
Some time ago I created a WikiTree profile for Harriet Newell and her husband because I figure that other genealogists might look for her in their family history. Recently I found family members for her and connected her to the global family tree. Katherine Patterson built a profile for Lorenzo Dow for the same reason that I profiled Harriet, but the other namesakes I found are still on my future to-do list.
Others of you probably have encountered similar situations. What other now-forgotten notable namesakes have you found? Are there enough of them to form a category?