The Hamilton firm is the successor to the Lancaster Watch Company, which itself grew out of the "Adams and Perry Watch Company" named after two "unfortunate" partners who failed to set up a watchmaking company for lack of capital. Their project in Lancaster in 1874 went from restructurings to re-foundations and it is therefore a completely different economic model that will bring the factory out of its rut. Hamilton takes its name from Andrew Hamilton, owner of the Lancaster site on which the factory is located.
Hamilton Watch was born from the merger of Lancaster Watch C° and Keystone Aurora Watch (Illinois), a company diversified in the manufacture of machines in particular. Among the founders of Hamilton Watch C° were investors in this new firm and the directors of Aurora Watch C°. Hamilton initially specialised in Railroad Watches, which represented a huge and rapidly expanding market from the end of the 19th century (after 1892, following the accident in Ohio). In 1927, Hamilton bought the Illinois Watch C° company, and then the Howard Watch C° manufacture in 1931.
During the Second World War, the firm will devote itself exclusively to the manufacture of military watches for the American armed forces in particular. Demand was so great that it justified the company no longer producing civilian watches. In February 1942, Hamilton manufactures 500 chronometers per month for the American Navy.
Hamilton distinguished itself with high-precision calibres, of which the 992 B is undoubtedly the most famous. The manufacture was also a pioneer in the use of the Elinvar. The Elinvar balance-spring patented in 1931 will be used in all the firm's movements thereafter. The Elinvar is revolutionary because of its elasticity and resistance to deformation whatever the temperature. The Swiss have been using it since the end of the 10's, particularly for uncut pendulums.
Hamilton exerts its talents in the 50s in the electric watch then probably diversifies a little too much to the point of getting lost while producing interesting watches until 1969. The firm produced under three different brands, Hamilton, Vantage and Buren, in six factories around the world. The brand will be associated with Heuer and Breitling for the manufacture of an automatic chrono in 1969. The brand then nested external movements, particularly Asian ones, before finally being acquired by Swatch Group in 1985.