Silversmiths were some of the first artisans to make snuff boxes. The United States, England, and Russia made the most silver boxes before 1850. I would expect any authentic snuff box from The United States to be marked. Most English boxes are marked. Most Russian boxes won’t be marked.
Silver snuff boxes come in all shapes and sizes. Most Russian boxes will be rectangular and have a lower profile. Boxes from England tend to be more oval and deeper. Virtually every snuff box will have some kind of design on it. English and American boxes have raised designed; whereas most silver snuff boxes from Russia have engraved designs.
Every country that snuffed made silver snuff boxes. However, the three countries above just made a much large quantity of boxes than all other countries combined. If you need help valuing your silver snuff box, just ask. We would be happy to freely share our opinion.