Copyright has always been for a limited term. Defining that limited term is a political judgment call, and I believe that the judgment is at this point wrong, erring in favor of unduly long copyright.
It is a safe bet that any book of 1957 still remembered (definitely Atlas Shrugged and On the Road, believe it or not The Anatomy of Criticism, probably not some of the others) has long since paid back the publisher's investment beyond expectations.
It is a safe bet that any book of 1957 still remembered (definitely Atlas Shrugged and On the Road, believe it or not The Anatomy of Criticism, probably not some of the others) has long since paid back the publisher's investment beyond expectations.