With many old pocket watches, it is difficult or even impossible to determine the exact date of production. In many cases, especially with lower grade European watches that were marketed under a variety of names, it is often impossible to even determine who the true manufacturer is. Many times, you have to rely solely on experience, comparing known examples to a watch at hand.
Most major American watch companies, on the other hand, kept relatively detailed production records, and it is often possible to determine the approximate date of an American made watch based solely on the serial number engraved on its movement (note that cases were made separately, often by entirely different companies, and on the serial number on the movement can be used to date a watch). In this chapter, I list approximate production dates based on serial number ranges for some of the more common American watch companies.
As for why the production dates are often only approximate, even for American companies that kept records, keep in mind that many companies stamped watch parts with serial numbers well in advance of the watch actually being assembled and sold. In addition, some companies reserved blocks of serial numbers in advance for certain models and grades, meaning that the serial numbers may not always be in strict chronological order. For these reasons, the actual date a particular watch left the factory may vary by as much as a couple of years from the date listed in the following tables.
To use the tables below, first determine the manufacturer of your watch. If it is one of the manufacturers listed below, locate the serial number on the watch’s movement (not the outer case). Then, in the appropriate table, locate the closest serial number that is higher than your watch’s serial number and look to the column immediately to the right to determine the approximate date. For example, if you had an American Waltham watch with a serial number of 7427102, you could determine that it’s approximate date of production was 1896 as follows: