This is likely the best online tool available for serial number look-ups on Hamilton watches. The reason for this is that it is electronically linked to the sales department ledgers, which detail the date finished and date sold for every movement, as well as the jobber to whom the movement was sold. Unfortunately, the NAWCC only has records up through serial number 800,000 or so, but none the less this is valuable resource for researching Hamiltons up to this point.
Lookup Serial Number
Please note that access to the Hamilton database requires membership in the NAWCC. NAWCC members must be signed onto the the NAWCC website through the Single Sign On(SSO) system.
This is yet another great resource to make your NAWCC membership worthwhile.