May 17, 2022

NYPL’s Sean Redmond on “Historical Copyright Records and Transparency”

From a New York Public Library Blog Post (approx. 3900 words) by Sean Redmond:

Last year, the Library began a pilot project to extract data from the Catalog of Copyright Entries (CCE) published by the U. S. Copyright Office. For background, all books published in the United States more than 95 years ago (before 1924 at the time of this writing) are in the public domain in the U.S.; all books published in 1964 and after are likely still in copyright.

Books published between 1924 and 1964 are potentially in the public domain if their copyright terms were not renewed 28 years after publication. To find out if such a book is still in copyright, one needs to find the notice of renewal published within the many thousands of pages of the Catalog of Copyright Entries or in an online database of renewals at Stanford University.

For those of us interested in digitizing books, information about a book’s copyright allows us to identify material that can be shared digitally. Finding out whether a book is not in copyright requires searching the CCE (and unlike the renewals, there was no database of registrations), finding the copyright registration, and confirming there is no corresponding renewal. Transcribing the CCE book registrations has made it possible to identify the registration and corresponding renewal.

Back in May, as soon as we had all the records, I crunched the data and made a rough estimate that 70% of the books from this time period might no longer be in copyright—around 480,000 public domain books—which raises the question: Has the Library made a list of all the public domain books?

Copyright and Transparency

The answer is, no, we haven’t, for the simple reason that failing to match a renewal alone isn’t enough to determine the copyright status of a work. The historical records are hard to use and, once you find the record, you need to apply a lot of outside knowledge to interpret it. The records we are interested in—books published between 1924 and 1964—were created for a copyright law that no longer exists and, being paper records, they weren’t updated.

For example, many foreign-published books were registered and entered the public domain in the US—and the US alone—when their copyrights weren’t renewed. That’s the story the records tell. What the records don’t say is almost all foreign-published books had their copyrights retroactively restored in 1994 by the Uruguay Round Agreements Act (more on this below) if they were still in copyright in their source countries. Copyright often depends not on a single act, like registration, but on a whole history of publication that can be complicated to tease out.

Learn More, Read the Complete Blog Post (approx. 3900 words)

See Also: Secretly Public Domain (July 22, 2019)

See Also: U.S. Copyright History 1923–1964  (May 31, 2019)

About Gary Price

Gary Price ( is a librarian, writer, consultant, and frequent conference speaker based in the Washington D.C. metro area. Before launching INFOdocket, Price and Shirl Kennedy were the founders and senior editors at ResourceShelf and DocuTicker for 10 years. From 2006-2009 he was Director of Online Information Services at, and is currently a contributing editor at Search Engine Land.