The public domain

No permission is needed to copy or use public domain works. A work is generally considered to be within the public domain if it is ineligible for copyright protection or its copyright has expired.

Public domain works can serve as the foundation for new creative works and can be quoted extensively. They can also be copied and distributed to classes or placed on course web pages without permission or paying royalties. 

Types of works

Categories of material that are generally not eligible for federal copyright protection include:

• Ideas and facts

• Works with expired copyrights

• Works with no original authorship

• Works governed by early copyright statutes that failed to meet the requirements for copyright protection, i.e., notice, registration, and renewal requirements (see the Rules of thumb, below, for details)

• U.S. government works (although works written by non-government authors with federal funding and works produced by state governments may be copyright protected)

• Scientific principles, theorems, mathematical formulae, laws of nature

• Scientific and other research methodologies, statistical techniques and educational processes

• Laws, regulations, judicial opinions, and legislative reports

• Words, names, numbers, symbols, signs, rules of grammar and diction, and punctuation

Public domain status by year published

There is no easy method to determine whether a work is in the public domain because the laws are complex and have changed numerous times over the years. This chart contains some rules of thumb that will help you confirm the copyright status of a work if you know when the work was created or published.

Copyright status rules of thumb
1. If the work was published in the United States prior to 1928, it is in the public domain.
2. For works published between 1928 and March 1, 1989, it depends on whether the certain statutory formalities were observed, such as providing a notice of copyright or following proper procedure for renewing the copyright.  See examples at right, or the Circular 22, “How to Investigate the Copyright Status of a Work" (pdf) from the U.S. Copyright Office	a. If the work was published in the United States between 1928 and 1978 without a notice, it is in the public domain. (Note: If the work published during this period has a notice, it may be protected for 95 years from the date of publication.)
	b. If the work was published in the United States between 1978 and March 1, 1989 without a notice and was not registered within the next five years, it is in the public domain. (Note: If the work published during this period has no notice, but was registered, it is protected for 70 years from the death of the author.)
	c. If the work was published in the United States between 1928 and 1963 with a notice, but copyright was not renewed, it is in the public domain.
3. After March 1, 1989, all works (published and unpublished) are protected for 70 years from the date the author dies. So, for example, the unpublished works of an author who died in 1943 are in the public domain as of January 1, 2014. For works of corporate authorship (works made for hire), the copyright term is the shorter of 95 years from publication, or 120 years from creation.