A bit after Public Domain day ( https://web.law.duke.edu/cspd/publicdomainday ) this year, but I think this is equally important. Without copyright extensions over the past 30 years, classics like The Cat in the Hat, West Side Story and Atlas Shrugged (how ironic) would now all be in the public domain.
Organize now to prevent Disney from extending copyright again
15 years ago, Congress kept Mickey Mouse out of the public domain. Will they do it again?