All Waltham pocket watches have a serial number stamped on the movement (the works) inside the watch. The serial number can be checked against an online Waltham pocket watch list, which will give the approximate year of manufacture. Waltham pocket watch serial numbers can be accessed by opening the case back.

Where is serial number on American Waltham Watch Company pocket watch?

Serial numbers to date the watch are only found on movements. The number on the case provides no information. Place the screw-down Waltham pocket watch face down in the palm of your hand.