Works in the public domain are not protected by copyright and may be used freely, without seeking permission. The term of copyright has been changed several times, but at the end of the copyright period, a work enters the public domain. Some works such as those produced by the federal government and public documents of state and local governments are generally in the public domain.

To determine if a particular work might be in the public domain use the chart, Copyright Term and the Public Domain in the United States, created for the Cornell Copyright Information Center by Peter B. Hirtle.

In the Public Domain

• Works whose copyright protection has expired such as those published before January 1, 1923
• Works produced by the federal government
• Works published between January 1, 1923 and 1977 without a copyright notice
• Works whose authors choose to place their work in the public domain (See Creative Commons licensing options)

Possible Public Domain

• Research reports and other work funded by federal government agencies that appear in commercial publications or databases
• Works published between January 1, 1923 and 1977 that did not have their copyrights renewed

Protected by Copyright

• Anything created after March 1, 1989

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More Information:

• Copyright Term and the Public Domain (Cornell Copyright Information Center)
  – includes international copyright terms
• Center for the Study of the Public Domain (Duke University School of Law)
• When Works Pass into the Public Domain (University of North Carolina)
• US Copyright Office Circular 15a: Duration of Copyright
• US Copyright Office Circular 15t: Extension of Copyright
• Creative Commons