For a fee, either private industry or the Copyright office will search the public records to figure whether the copyright was renewed. For such co-published works, the copyright expires when both 75 years have elapsed and the author's life plus 50 years have elapsed. In general, the author of a work is the original owner of its copyright. The execption to this rule is when another individual or organization hires you to write the work. For 'work for hire', any copyright notices should list the hiring organization instead of the the actual author.
Copyrights are a form of property that can be bought, sold, inherited, etc.
All rights reserved.