Changes

Under Section 105 of the copyright law, "Copyright protection under this title is not available for any work of the [[United States]] Government, but the United States Government is not precluded from receiving and holding copyrights transferred to it by assignment, [[bequest]], or otherwise."

Under Section 105 of the copyright law, "Copyright protection under this title is not available for any work of the [[United States]] Government, but the United States Government is not precluded from receiving and holding copyrights transferred to it by assignment, [[bequest]], or otherwise."

The duration of U.S. copyright has changed several times.  It was 14 years as originally enacted, then doubled to 28 years, and an option for creators to renew that for another 28 years was added.  In 1976, under pressure from foreign countries (which had copyright terms extending 50-70 years after the death of the creator, even for works created when they were young) and from large entertainment corporations such as Disney (which had valuable properties whose copyrights were in danger of expiring) Congress extended the duration of copyright to 75 years.  Two decades later, they added another 20 years.  Neither of these extensions applied to copyrights that had already expired, so anything published in the United States before 1923 is in the [[public domain]] in that country.<ref>http://www.copyright.cornell.edu/training/Hirtle_Public_Domain.htm</ref>  Also, photographs of paintings in the public domain would ordinarily not qualify for copyright protection either.<ref>''[[Bridgeman Art Library v. Corel Corp.]]''</ref>

The duration of U.S. copyright has changed several times.  It was 14 years as originally enacted, then doubled to 28 years, and an option for creators to renew that for another 28 years was added.  In 1976, Congress extended the duration of copyright to 75 years.  Two decades later, they added another 20 years.  Neither of these extensions applied to copyrights that had already expired, so anything published in the United States before 1923 is in the [[public domain]] in that country.<ref>http://www.copyright.cornell.edu/training/Hirtle_Public_Domain.htm</ref>  Also, photographs of paintings in the public domain would ordinarily not qualify for copyright protection either.<ref>''[[Bridgeman Art Library v. Corel Corp.]]''</ref>

Works that were published before March 1, 1989 required a copyright notice, such as the word "Copyright" or "&copy;", along with name of the copyright owner.<ref>http://fairuse.stanford.edu/Copyright_and_Fair_Use_Overview/chapter8/8-a.html</ref> (The approximation "(c)" was widely used, but invalid.) There are some narrow exceptions to this rule, and the lack of a notice on an unauthorized copy does not entitle one to copy the work.  Works published after that are protected by copyright laws even if they lack the notice.  Registration of copyrights is optional, but you need to have the work registered to sue for damages.  These changes were mandated by the [[Berne Convention]], an international copyright regime.

Works that were published before March 1, 1989 required a copyright notice, such as the word "Copyright" or "&copy;", along with name of the copyright owner.<ref>http://fairuse.stanford.edu/Copyright_and_Fair_Use_Overview/chapter8/8-a.html</ref> (The approximation "(c)" was widely used, but invalid.) There are some narrow exceptions to this rule, and the lack of a notice on an unauthorized copy does not entitle one to copy the work.  Works published after that are protected by copyright laws even if they lack the notice.  Registration of copyrights is optional, but you need to have the work registered to sue for damages.  These changes were mandated by the [[Berne Convention]], an international copyright regime.