On Monday, the Nelson-Atkins Museum announced that its wonderful Grand Canyon painting by Thomas Moran, from 1912, would grace a Forever stamp as part of an homage to the Hudson River School of artists — it’s one of four tributes.

What are the other three paintings? (I got no other press notices.) Were the other three museums, as the Post Office would choose only from works held in the public domain, mum on the honor? Guess so. But I looked it up.