Answered By: [Unclaimed] Last Updated: Nov 16, 2015 Views: 31
Generally, most works enter the Public Domain because of old age and unprotected by copyright law. This includes any work published in the United States before 1923, or because they were published before 1964 and the copyright was not renewed (a requirement for works published before 1978).
A smaller group of works fall into the public domain because they were published without copyright notice (copyright notice was necessary for works published in the United States before March 1, 1989). Additionally, some works are in the public domain because the owner has indicated a desire to give them to the public without copyright protection.
Public Domain Chart Timeline of when a work/s pass into the Public Domain.
( Thanks to: Laura Gasaway, Director of the Law Library and Professor of Law at the UNC.)
Updated November 2015