For nearly 100 years, the company's manufacturing complex in Elgin, Illinois, was the world's largest site dedicated to watchmaking.

[2] The growing young city of Elgin, Illinois, some 30 miles northwest of Chicago, was chosen as the factory site.

It moved into the defense industry,[4] manufacturing military watches, chronometers, fuzes for artillery shells, altimeters, and other aircraft instruments and sapphire bearings used for aiming cannons.

The original, obsolete factory in Elgin closed in 1964 after having produced half of the total number of pocket watches manufactured in the United States (dollar-type not included).

[5][6] The company maintained a leased building in Elgin that housed offices and casing, fitting, shipping, service, and trade material departments until about 1970.

The company discontinued all US manufacturing in 1968 and sold the rights to the name "Elgin", which were subsequently resold multiple times over the years.