[lIl-IIIl]

I think that comment was about Twain's autobiography, not Grant's:

https://en.m.wikipedia.org/wiki/Autobiography_of_Mark_Twain#....

I remember when it first came out, which was surprisingly recently, in 2010.

They published it in secret in 2001 so that it is not considered "unpublished" and doesn't enter public domain in 2003. Although I don't understand how "publishing in secret" is still considering publishing.

[bryanrasmussen]

hmm, well Twain was quite committed to the idea of perpetual copyright, so seems fitting somehow.