Page:The librarian's copyright companion, by James S. Heller, Paul Hellyer, Benjamin J. Keele, 2012.djvu/34

18 Unfortunately for users, a work that has fallen into the public domain will not necessarily stay there. In a recent case, the U.S. Supreme Court ruled that Congress can reinstate copyright protection for materials that were previously in the public domain.

The Bottom Line: Copyright, like the Gary White tune (made famous by Linda Ronstadt), lasts a long, long time. To help you see things more clearly, we offer this simplified chart and a more detailed chart in.