“Pilgrims Progress comes to mind.”
That book would probably be #1 on a list of books that used to be very popular but which are completely obscure today.
I finally read Pilgrim’s Progress when I realized that almost every character in every 19th C. novel I’d ever read had read it!
I liked it OK and thought it held up well for something so old and rather strange. Some parts of it have really stuck with me.
It's an abridged text from the early 19th century, by Mary Godolphin, it keeps all the essentials of the story AND the language style.
Lawson's illustrations are wonderful.