There have been some recent letter-sequence puzzles that have been well-received. For example,
Three different, and somewhat difficult, sequence puzzles
Yet another batch of four sequence puzzles
So I thought I'd try to make one. I include only one puzzle here, instead of many, like other posts, so that it is obvious who to award the answer to.
There are 9 items in this list. The first 8 of them are represented by the letters below.
Find the last one.
S N A X M P N I _
Hint:
This list was published anonymously during the first 25 years of the 19th century, but 14 years later, someone claimed authorship.