As the Copyright Office notes in its circular on International Copyright protection, "There is no such thing as an 'international copyright” that will automatically protect an author’s writings throughout the world. Protection against unauthorized use in a particular country depends on the national laws of that country." That said, the circular goes on to discuss protections afforded by various multilateral treaties. Information on the treaties, which as the Berne Convention and the WIPO Copyright Treaty can be located at the World Intellectual Property Organization's website.
In a similar vein, the Digital Public Library of America, Creative Commons, and Europeana are working on establishing international and interoperable rights statements. More information can be found here.
Creative Commons is a concept related to copyright that allows for both the sharing of intellectual property while retaining the rights the creator wants to retain. It does not replace a copyright, nor does putting one's work under a Creative Commons License move materials to the public domain. For example, one might want people to be able to access music created by them while not wanting the music to be used in commercial settings. This allows for greater sharing and collaboration.
For more information, check out the Creative Commons website.
Copyright is the legal protection of the expression of ideas, such as
What is in the public domain can be confusing and simple at the same time. If one looks at the chart created by Cornell University, many different possibilities exist. However, there is a simple rule of thumb involving published, copywritten works:
The Boston Public Library holds the Catalog of Copyright Entries. Unfortunately, after the August 1998 flood in the building, the collections are no longer complete. For those we are missing in print, there is microfilm available.
The copyrights are grouped in different parts, and there were different series.
Series 2 (1906-1946) is divided as follows:
Series 3 (1947-1977) is divided as follows:
Since 1978 the Catalog of Copyright entries have been online.