My previous post was in error. I just googled " How long does a copyright last" and the following came up.
"70 years
All works published in the United States before 1923 are in the public domain. Works published after 1922, but before 1978 are protected for 95 years from the date of publication. If the work was created, but not published, before 1978, the copyright lasts for the life of the author plus 70 years.Mar 27, 2013"
Sorry for the misinfo.
This was done because Mickey Mouse was coming up for release into the public domain, and Disney was fit to be tied. So they used their considerable money and influence to get the US law changed.
[youtube]https://www.youtube.com/embed/SiEXgpp37No[/youtube]
This 70 years only applies to the United States. Copyrights (and patents, for that matter) are not a universal, natural law truth like private ownership, exclusiveness of marriage, wrongness of murder, etc. This 70 years isn't a declaration by God regarding how long a work is under copyright. On the contrary, it's a declaration by a masonic government which was only uttered to further enrich the Disney Corporation. I don't think that morally obliges.
Oh, and Disney is the worst hypocrite, because they ripped off so many works of art (public domain and otherwise) for virtually all of their famous movie franchises.
[youtube]https://www.youtube.com/embed/L6D6w8OBA6c[/youtube]