Thanks, Hal.  Several people have written to me about the McGuffey Readers, and also mentioning Power's biography.  I've always wondered about the McG references, though; it's a fairly circular conversation, and I suspect at the bottom isn't any hard document but rather the first scholar who said, "Well McGuffey Readers were common then, so Twain must be referring to them"--and then everyone else repeated him.  I've read a LOT of 19th century textbooks for this chapter, and there were a great deal of them out there to choose from.

I agree that the Sunday School books and the text books--especially reading books--were pretty much alike.  I have notes on one primer in which the author suggests that the Bible be taught concurrently.  --s

Susan K. Harris
University of Kansas