The life of the author, plus 50 years (Canadian Copyright) after the death of the author. Always ending December 31 in it's last year, regardless of when the copyright was filed. Source - the Canadian Copyright Office http://www.ic.gc.ca/eic/site/cipointern … 1.html#q10
The life of the author, plus 70 years (American Copyright) after the death of the author. This is different if the work is done under a psuedonym, anonymous, or for hire. Lasting up to 95 years or a 120 years from the time of the year it's registered. Source - the American Copyright Office http://www.copyright.gov/help/faq/faq-d … l#duration
I'll assume you meant North America. If it's another country, just google country + Intellectual Property Office.