Originally Posted by Fbone
I am grateful for all the hard work the contributors put into the library.
Unfortunately, for US residents current copyright laws prevent us from adding anything published after 1922.
Not entirely true--anything through 1963 that wasn't renewed is eligible, and some things published later than that didn't have the right kind of copyright notice & therefore are in the public domain. (Almost nothing that's actually books is in this category; it includes things like newsletters, fanzines, and various amateur publications.)
Pre-1922 is *definitely* in the public domain in the US; between 1923 and 1963 is maybe (but if it's well-known today, that's probably because it was renewed); post-1963 is PD only by bureaucratic glitch or author's intentional release.
And there are Creative Commons/open source texts that could be reformatted for MR readers; a lot of those are released by the author/publisher in PDF format and need reworking to be easily readable on most devices.