The Hamilton Watch Company has manufactured and marketed timepieces since 1893 when it produced its first watch, the 936. During the expansion of the railroads in the U.S, Hamilton maintained over 56% of the market. Railroads purchased all of Hamilton’s production. As the market switched from pocket watches to wrist watches after World War I, the company manufactured wrist watches. During World War II, the company was also extremely successful in producing marine chronometers and deck watches in large numbers to fill the needs of the United States Navy, and other Allied navies as well (Model 21, Model 22).Hamilton’s ,Ventura watch was worn by the “legend” Elvis Presley in the movie “Blue Hawaii” in 1961. The model is still on production in many variations. From 1971 it is one of twenty brands belonging to the Swatch Group, the world’s largest watch manufacturer and marketer.