What is the public domain?

Public Domain Frequently Asked Questions
What is the public domain?
Public domain works are not restricted by copyright and do not require a license or fee to use. Public domain status allows the user unrestricted access and unlimited creativity!

There are three main categories of public domain works:

Works that automatically enter the public domain upon creation, because they are not copyrightable:
Titles, names, short phrases and slogans, familiar symbols, numbers
Ideas and facts (e.g., the date of the Gettysburg Address)
Processes and systems
Government works and documents1
Works that have been assigned to the public domain by their creators
Works that have entered the public domain because the copyright on them has expired
(Note: Use of some works, such as ideas and symbols, may be restricted by other laws, such as patent, trademark, or trade secret.)

What works have expired into the public domain?2
All works published in the U.S. before 1923
All works published with a copyright notice from 1923 through 1963 without copyright renewal
All works published without a copyright notice from 1923 through 1977
All works published without a copyright notice from 1978 through March 1, 1989, and without subsequent registration within 5 years
Congress has passed a series of laws extending the term of copyright. Currently, the default term is life of the author plus 70 years. That means that most of the copyrighted works created from the late 1970s to the present may not become public domain during your lifetime.

In general, works published after 1977 will not fall into the public domain until 70 years after the death of author, or, for corporate works, anonymous works, or works for hire, 95 years from the date of publication or 120 years from the date of creation, whichever expires first.

Where can I find public domain works?
The sites below will guide you to a cultural wealth of public domain books, images, illustrations, audio, and films where the copyright term has expired or the creator has not renewed the license. Remember, public domain works are free and available for unrestricted use. Enjoy and be creative!

Smithsonian Institution Public Domain Images
New York Times Public Domain Archives
Project Gutenberg, a collection of public domain electronic books
Librivox, public domain audio books
Prelinger Archives; a vast collection of advertising, educational, industrial, and amateur films.
How does a creator dedicate a work to the public domain?
One way to dedicate a work to the public domain in the U.S. is to use the Creative Commons Public Domain Dedication. Note that interpretation of a dedication may vary in countries outside of the United States.

Creative Commons also offers “CC0,” a method of waiving all copyrights and a number of other related rights