This media file is in the public domain in the United States. This applies to U.S. works where the copyright has expired, often because its first publication occurred prior to January 1, 1929, and if not then due to lack of notice or renewal. See this page for further explanation.
This image might not be in the public domain outside of the United States; this especially applies in the countries and areas that do not apply the rule of the shorter term for US works, such as Canada, Mainland China (not Hong Kong or Macao), Germany, Mexico, and Switzerland. The creator and year of publication are essential information and must be provided. See Wikipedia:Public domain and Wikipedia:Copyrights for more details.
It is an anonymous work or pseudonymous work and 50 years have passed since the date of its publication (or creation, whatever date is the latest)
It is a photographic work, and 50 years have passed since the date of its creation
It is another kind of work, and 50 years have passed since the year of death of the author (or last surviving author)
It is one of "official texts of legislative, administrative or legal nature and their official translations"
Before July 5, 2009, a photographic work was protected for 25 years. Pictures created before July 5, 1984 have already been placed into the public domain.