Works enter the public domain in several ways:
Works in the public domain may be copied, republished, or otherwise used without worrying about copyright infringement.
There are two very useful charts on when materials pass into the public domain. One was done by Lolly Gasaway of the University of North Carolina. The other one is provided courtesy of Peter B. Hirtle from the Cornell Copyright Information Center. The American Library Association has commissioned this online public domain tool. It works best when applied to print resources. Other formats often have several overlaping copyright holders.
Stanford University maintains the Copyright Renewal Database. "This database makes searchable the copyright renewal records received by the US Copyright Office between 1950 and 1993 for books published in the US between 1923 and 1963." The database contains only book renewals. This time period is one of the most difficult in determining whether a copyrighted book passed into public domain by not having the copyright renewed.
The information on this site is intended to
inform the faculty, staff and
students at the College of DuPage about copyright and to provide guidelines
for using and creating copyrighted material. The information should not
be considered legal advice.
For more information contact The Library