The Hamilton Watch Company was established in 1892 in Lancaster, Pennsylvania. In its early years, Hamilton was a dominant producer of watches for the American railroads, and during World War Two, the company’s entire production was dedicated to the military.
In 1966, Hamilton acquired the Buren Watch Company, of Buren an der Aare, Switzerland. From 1966 to 1969, Hamilton Lancaster and Buren Switzerland were operated as a joint concern, with Hamilton using a number of Swiss movements for their “American” watches and Buren utilizing a number of components manufactured by Hamilton Lancaster.
When Heuer and Breitling created their joint venture in an effort to produce the world’s first automatic chronograph, Hamilton-Buren was brought in as a partner, as Hamilton-Buren was using a micro-rotor that was well-suited for the new movement. During the 1960s, Heuer produced manual-winding chronographs that were sold under the “Hamilton” name, and when Heuer introduced its Caliber 11 automatic chronographs, a line of these watches was also produced for Hamilton.