Copyright Information

Public Domain

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 and public documents of state and local governments
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