I did some digging, and here is what I found: "This is the Nunns & Clark square piano from 1853, a masterpiece of American Victorian craftsmanship featuring a rosewood case, mother-of-pearl key covers, tortoiseshell veneers on accidentals, and abalone inlay, built in New York City for display at the 1853 Crystal Palace Exhibition."

It's at the Met in NYC. So while theoretically it is playable, they wouldn't let you.

Source - a lot more info on the piano: https://www.metmuseum.org/art/collection/search/503678

Probably still works. The actions on these old pianos are fairly robust.

Looks like its behind glass. There seems to be a reflection in the right corner, but I can't tell for sure.