From:
http://copyright.cornell.edu/resources/ ... ootnote_20
Anything published before 1923 is open to public domain without protection.
Anything published between 1923-1963 with copyright notice but not renewed is open to public domain.
Anything published between 1923-1963 that had its copyright renewed is off limits for 95 years after publication date.
Quote:
There are a few ways to find out whether a copyright was renewed. Some are easier than others; some are more definite in their answers than others.
One easy way to check, sometimes, is just to see if there was any edition published more than 28 years after the original edition, and see if there's a renewal notice in that newer edition. This doesn't always work-- a lot of books simply don't get reprinted-- but if there is such an edition, it can be an easy check to make.
Another way that doesn't involve an exhaustive copyright record search is to write to the author, or their agent or estate, or to the last publisher of the book, and see if they can tell you whether the book's copyright was renewed. Of course, you might not always be able to reach them, and they might not always cooperate, but people on the Net have done this before and found out what they wanted to know. Sometimes, even if the copyright has been renewed, by mailing them you might be able to convince them to let an edition go online anyway.
It's also possible to do a search yourself of the copyright records. For 1978 onward, they're online at the Copyrigh Office. Most book-related renewal records from years from 1950 to 1977 are now also online at least in page image form.