How did It's a Wonderful Life fall into the public domain when so many other movies of that era haven't? I often wonder how many other buried gems we're missing out on.
At the time it was created, the default copyright term was 28 years, with an additional 28 if renewed. The owners of the rights to the movie neglected to renew it, and it fell into public domain in 1974. Anything not in public domain in 1976 had its term extended by a new copyright act, and then extended again in 1998.