Most US government publications are are public domain: https://www.copyrightlaws.com/copyright-laws-in-u-s-governme...
But determining the copyright status of anything old is really much harder than it should be.
But determining the copyright status of anything old is really much harder than it should be.
Repeating a point of my original question, in case you have something to say about it: "112 gripes" was published in 1945, thus sites like https://www.biblio.com/blog/2010/07/how-to-determine-if-a-bo... suggest it's expired . But also, it was republished in the US in 2004 (ISBN 1-4191-6512-7). Does this make it "freshly-re-copyrighted until 2004 + 70 years?", or is the year that counts for copyright the original publishing date?
EDIT okay forget about the re-publish question, another HNer commented about it.