In the US it is not necessary to file a copy with the Library of Congress & apply for a copyright in order to have the copyrights.
Copyright is also automatic in Australia. It is not necessary to register anything.
Anything published before 1961 is now out of copyright.
There is a regulation that stipulates a minimum of 50 years for copyright in relation to international trade law, but individual countries have their own copyright terms. See http://en.wikipedia.org/wiki/List_of_countries%27_copyright_length.