Works in the public domain have expired, forfeited, or inapplicable intellectual property rights. This includes books published prior to 1923, works published by the U.S. Federal Government, or other items placed in the public domain by the copyright holder. There are exceptions to this rule, primarily considering orphan works, perpetual copyright and works created by government contractors, but the public domain offers a wealth of history and resources.

Google Books - Google is digitizing books and making all those in the public domain available online to read in full and download. A vast range of subject areas are covered. Limited previews are often available for book still protected by copyright.

At the top of your results list, select Free Google eBooks beneath the Any Books dropdown to to only get results that you can read in full and download.