I read "The duration of the U.S. protection for all other works… was for 70 years from the artist’s date of death" and thought wow, did Mondrian really live into the 1960s or so? Next paragraph: "Mondrian died in 1944. Any of his works subject to a life-plus-70 regime would have entered the public domain" 10 years ago. Who even thought of including that in a legal argument??
https://en.wikipedia.org/wiki/Copyright_law_of_the_United_St...:
“For works published or registered before 1978, the maximum copyright duration is 95 years from the date of publication, if copyright was renewed during the 28th year following publication. Copyright renewal has been automatic since the Copyright Renewal Act of 1992.
For works created before 1978, but not published or registered before 1978, the standard §302 copyright duration of 70 years from the author's death also applies. Prior to 1978, works had to be published or registered to receive copyright protection. Upon the effective date of the 1976 Copyright Act (which was January 1, 1978) this requirement was removed and these unpublished, unregistered works received protection. However, Congress intended to provide an incentive for these authors to publish their unpublished works. To provide that incentive, these works, if published before 2003, would not have their protection expire before 2048.”