A study of the copyright renewal rate for maps

This study examines the copyright renewal of maps published in the United States from 1923 to 1950 and compares the results with a recent study of copyright renewals for books. Results indicate that, while the average copyright renewal rate for maps appears similar to that of books, the average was skewed higher by a single publisher whose renewal rate was much higher than average. With the data from that publisher excluded, the average copyright renewal rate dropped to 10%, meaning that a significant number of maps copyrighted in the United States in the first half of the 20th century are probably in the public domain due to lack of copyright renewal. This has implications for library map digitization projects, as much more content may be available for scanning and archiving than was previously thought.