Works that are considered in the “public domain” may be used (i.e., copied) freely, without fear of infringing on copyright.
The following categories of publications are generally considered to be in the public domain; that is, their use is not protected by copyright law:
- U.S. works whose copyright has expired;
- works where the creator has given up their copyright;
- works created by the federal government, for example, data files from the 1990 Census
The Sonny Bono Copyright Term Extension Act, signed into law on October 27, 1998, amended the duration of copyright protection by extending copyright terms for an additional 20 years. Specific provisions are as follows:
- For works created after January 1, 1978, copyright protection will endure for the life of the author plus an additional 70 years. In the case of a joint work, the term lasts for 70 years after the last surviving author’s death. For anonymous and pseudonymous works and works made for hire, the term will be 95 years from the year of first publication or 120 years from the year of creation, whichever expires first;
- For works created but not published or registered before January 1, 1978, the term endures for life of the author plus 70 years, but in no case will expire earlier than December 31, 2002. If the work is published before December 31, 2002, the term will not expire before December 31, 2047;
- For pre-1978 works still in their original or renewal term of copyright, the total term is extended to 95 years from the date that copyright was originally secured.
For more on the public domain, see Stanford University’s Copyright and Fair Use website.
Determining public domain status
Refer to the detailed guide developed by Peter B.Hirtle of Cornell University for help in determining a work’s copyright status: Copyright Term and the Public Domain in the United States.