An aside:
Where does one go to find out if a specific writing is in public domain?
:)
Unfortunately disney and others have purchased enough legislooters to expand the reach of copyright so far beyond its original intent as to make modern copyright unrecognisable as compared to that instituted under the fine fellows who founded this republic.
There is no central registry of copyright. The only way to determine if a work is public domain is to contact the publisher (if that is even possible). There is quite a bit of information about copyright at Project Gutenberg. The general rule of thumb is that works published before 1920 or so are public domain.
As a side note, you might recall that disney produced a cartoon of "Jungle Book" in the late 60s. At the time it was completed, (but not when it was started BTW), the copyright on Kipling's work had expired. If copyright had been as severely bastardized at the turn of the last century as it is today, they would not have been able to rip off Kipling's works for free as they did then until next year!
Personally, I have no respect whatsoever for anything under copyright beyond 30 years.