Items Are in the Public Domain for One of Three Reasons
1. They are ineligible for copyright. In the US, this includes works created by the US Government;
2. Their copyright term has expired; or
3. They are granted to the public domain by the creator or their agent (i.e., the rights holder).
Because of its emphasis on literary works, Project Gutenberg has mostly focused on items for which the copyright term has expired. Until 1998, this included items published 75 years earlier. For example, items from 1920 entered the public domain when their copyrights expired in 1995. The US Copyright Term Extension Act of 1998 changed the term to 95 years for most literary works, so new items (from 1923 onward) will not enter the public domain before 2019.
Figure 2: Michael Hart’s sunroom workspace in his Urbana home
There are over one million published works from 1923 and earlier, and these are the main items that Project Gutenberg continues to digitize and distribute. In addition, there were approximately one million works published in the United States from 1923-1964 but not renewed. Those items entered the public domain when their first copyright term ended, 28 years after publication. The copyright procedures utilized are online at Copyright procedures