Originally posted by lguckert79 their are on film like the film we use today but they are huge they are i think 3'' by 2''.
Those would be 2 1/4 x 3 1/4 inch negs (6x9cm) from a 120-film folding camera. Such was very popular in USA from around 1910-1960 because a home developer could make usable contact prints without needing an enlarger or much darkroom space. The film is still available. Those kinds of cameras can be found used, cheap. I have a couple, and they're pretty fun to use.
Yes, check with a museum. Scan them if you can. Who knows, if you post the images, you could have another two-day internet frenzy!