If you've taken the copyright awareness class through CaseLearns, you know that you can double-check a copyrighted work to see if it has passed out of legal protection in to the public domain. You also know that copyright terms are complex due to changing laws, and that while pre-1923 works have passed into the public domain, there are other periods of time where shorter terms & renewals have made it a challenge to identify a work's protection status.
Peter Hirtle (Cornell University) writes one of the most-used copyright term charts, listing unpublished works as well as international ones, and it is used in the CaseLearns copyright class, along with a shorter chart by Laura Gasaway (UNC-Chapel Hill), also well-used in the U.S. Two weeks ago, Hirtle updated his expanded chart to include information on sound recordings and architectural works. Now twice the original size, with wonderful footnotes that are themselves illuminating, you can view it online and click through to the footnotes, or print a PDF version to keep for your reference.
Copyright@Case, copyright awareness web pages, has links and general information for your use. Find both charts in the middle of the page, in the link for "Public Domain Charts." You'll also find a sidebar of links for more web resources, common copyright myths, and a contact link for asking questions.
