From The Legal Genealogist:
The Legal Genealogist trusts that — by now — readers understand that copyright lasts for some time after the death of the person who created the work: the book; the photo; the painting.
Around the world, the minimum time generally is 50 years after the death of the creator. In the United States, it’s generally 70 years after the death of the creator.
What may not be as well understood is who owns the copyright at that point — and how that person comes to own it.
Here’s the link to the full article at The Passive Voice, plus Mr. PG’s solid advice:
The bottom line for your copyrights and everything else you own is that your heirs will be very grateful to you if you have a will.