Each country has it’s own laws on public domain, Creative Commons, and copyright.  Please research your country’s policies.  Here are some resources on copyright.

United States– https://www.copyright.gov/title17/

In the United States, any works published before 1923 are free of copyright.  Any works published after 1923 are no longer copyrighted 70 years after the creator’s death. 

European Union– https://ec.europa.eu/digital-single-market/en/eu-copyright-legislation

In Europe and Great Britain, works are free of copyright 70 years after the death of the author.  There are special exceptions for works published during World War I and II.

Australia – https://www.ag.gov.au/RightsAndProtections/Documents/ShortGuidetoCopyright-October2012.pdf

In Australia, works are free of copyright 70 years after the death of the author.

New Zealand– http://www.copyright.org.nz/

In New Zealand, works are free of copyright 50 years after the death of the author.