In 1928 Hamilton Watch Company purchased the Illinois Watch Company and... then the Great Depression happened. Within a few years the Illinois Watch Company was no-more and whatever could be salvaged was moved to Lancaster, PA.
The Illinois Watch Company was a well known American manufacturer with a great line up of wrist and pocket watches. It was a great opportunity to expand Hamilton's business, gain economies of scale, and benefit from the technological synergies that Illinois offered.
Shortly after the acquisition, Hamilton introduced their Explorer series with Hamilton-branded movements based on Illinois designs.
Illinois continued to make watches for a while and one of them was the Illinois Ritz. The Ritz is a unique model in that it was offered in a two-tone white & yellow case - a very popular option.