Answer: Under U.S. law, there is a different copyright duration for works created before January 1, 1978 and those created thereafter. The current Copyright Act of 1976, which actually became effective on January 1, 1978, changed copyright duration from a term of years (then a maximum of two 28-year terms or 56 years total) to a “life of the author plus…” regime more in keeping with the rest of the world. However, the new “life plus” regime only applied prospectively to works created on or after January 1, 1978. Pre-1978 works were still subject to a fixed term of year copyright duration. The Sonny Bono Copyright Term Extension Act of 1998 engendered further changes, creating a shifting maze of applicable time periods.
Nevertheless, the following rules-of-thumb should be helpful for determining whether a printed work is in the public domain in the U.S. (please bear in mind that these are generalities subject to some exceptions):
- If a work was first published prior to 1925 (that is in 1924 or earlier), it is public domain in the U.S.
- The duration of copyright for works first published in 1925 through 1977 is 95 years from the date of publication.
- The duration of copyright for works created on or after January 1, 1978 to the present, is life of the author plus 70 years.
Other countries have their own separate copyright laws and durations. International treaties, such as the Berne Convention, prescribe certain minimum copyright durations, but individual countries are free to exceed these minimums. Consequently, certain works may fall into the public domain in one country and still be protected within the territory of another. In Canada, copyrights subsist for a term of life of the author plus 50 years. There are many works that have fallen into the public domain in Canada because the author has been deceased for at least 50 years, but remain protected in the United States because the work was first published after 1924. Conversely, there are some pre-1925 U.S. publications that are public domain in the U.S., but remain protected in Canada because the author has not been deceased for at least 50 years.
The United Kingdom and most of Europe provide a copyright duration of life of the author plus 70 years. However, some countries, such as France, extend copyrights even longer for authors who lived through one or both of the World Wars. Some countries extend a shortened copyright protection term to newly discovered and published editions, even if no new material is added.
Consequently, when searching for globally clear PD content, the work in question ideally should have been published before 1925 and the author should have been deceased for at least 70 years, or even 78 years. While all works may have certain nuances that may affect public domain status, these minimum benchmarks are a good starting point for clearance purposes.