Instructors, if you are planning for your fall classes, this chart might be useful. It is slightly old, 2001, but most of the components are the same. I will have to do some research to see if there have been any updates, but I don't think there are.
Copyright Term and the Public Domain in the U. S.
If you wish to print or publish on the Internet the works of others, this chart will help you decide whether the copyright police can throw you in the clink.