How do I find out how old my pocket watch is?

The most reliable way to date a pocket watch is the serial number on the movement, not the one on the case. Cases and movements were often sold separately, so the case number tells you little. Open the back carefully (many unscrew, some pry open at a small notch) and look for the maker's name and a long number engraved on the metal plate of the works.

Major American makers like Elgin, Waltham, Hamilton and Illinois kept serial number records, and published lists match those numbers to production years and grades. A quick search for the maker's name plus "serial number lookup" will usually get you within a year or two.

Other clues help too. Key-wind watches, which need a separate key, are generally older than stem-wind models. A movement marked "Adjusted" with 21 or more jewels and a lever-set mechanism may be a railroad grade watch.

If the back won't open easily, stop. A jeweler or watch repair shop can open it safely in a minute without scratching the case.