Copyright on pre-1923 National Geographics

Dear Rich: Is it possible for works published before 1923 to have had their copyrights renewed and therefore protected? I read that National Geographic and some other magazines had their pre-1923 publications renewed and was wondering if this information is correct. It's possible that pre-1923 National Geographic magazines may have been renewed at some point, but even if they were, they are no longer protected under U.S. copyright law. Like the 5.4 million pre-1923 published books still existing, they are definitely in the public domain. If you need more info on the public domain, check out our favorite resource. Regardless of their copyright status, those old NatGeo issues may or may not (or definitely don't) have any value.