| Reliance Automatic Lighting Co. | Racine, Wisconsin. Maker of electric time switches, windup and synchronous. | | | Yes |
| Regent Mfg. Co. | Chicago. Made cast front cases that often housed Western Clock Clock Manufacturing Company or Western Clock Company movements. | | | No |
| Plymouth | Name used by Seth Thomas in the 1930s - 1950s for a lower priced lines of clocks. | Seth Thomas | | No |
| Parker | Maker of alarm clocks in Meridan, Connecticut, ca. 1893 - 1934 | | | Yes |
| New Haven | Chauncey Jerome (1793–1868) was an important figure in early American clock manufacturing. In 1816 he worked for Eli Terry and made the first pillar and scroll cases (to house wooden movements). In . . . | | | Yes |
| New England Watch Company | The Waterbury Watch Company was renamed the New England Watch Company in 1898. In 1914 Ingersoll purchased the New England Watch Company. | | | Yes |
| M. S. BENEDICT MFG. CO. | EAST SYRACUSE, N. Y. Maker (or marketer) of cast front clock cases. | | | Yes |
| Montgomery Ward | Mail order and department store retailer who marketed some clocks with their name on it. | | | Yes |
| Minneapolis Honeywell | Minneapolis-Honeywell was created by the merger of Honeywell Heating Specialty Company and Minneapolis Heat Regulator Company in 1927. (Source Wikipedia) | | | Yes |
| Mido | A watch company founded in Switzerland in 1918. Well known for their Multifort line of wrist watch waches which are self-winding, waterproof and shock resistant. Today Mido is part of the Swatch Group . . . | | | Yes |
| Lux | The Lux Clock Manufacturing Company was founded in 1914 by Paul Lux. | | | Yes |
| Kundo | Base company for Kieninger & Obergfell. Maker of 400 day clocks. | | | Yes |
| Kern and Sohn | German maker of 400 day clocks in the 1950s. | | | Yes |
| Kenmore Kodel | Kenmore clocks by The Kodel Electric & Manufacturing Co., 517 East Pearl St., Cincinnati, Ohio. | | | Yes |
| Junghans | Maker of clocks and watches, still in existence, founded in Germany in 1861. | | | Yes |
| Ingraham | Elias Ingraham (1805–1885) was born in Marlborough, CT, and became a famous clock case maker and designer. In 1828 he came to Bristol, CT to design and make clock cases for George Mitchell, a succes . . . | | | Yes |
| Ingersoll | The Ingersoll Watch Company started as mail order business (R H Ingersoll & Bro) started in New York City in 1882 by 21-year-old Robert Ingersoll and his brother Charles Ingersoll. | | | Yes |
| Imperial Co. | Chicago. Maker of cast front clock cases. | | | Yes |
| Illinois Watch Company | Springfield, Illinois. | | | Yes |
| Hytron Corporation | Manufacturer of vacuum tubes. Bought out by CBS in 1951. Advertisements state that Hytron developed the GT tube starting in 1938, and the first miniature (baseless) tube also in 1938. Company location . . . | | | Yes |
| HECO | Henry Coehler Company, New York. Importer of 400 day and cuckoo clocks, dealer for Junghans clocks in the 1950s | | | Yes |
| Haydon | Forestville, Conn and other locations. Makers of electric synchronous motors. | | | Yes |
| Hammond | Hammond Clock Company was founded in 1928 to produce electric clocks with a manual-starting synchronous motor. The company became known as the Hammond Instrument Company in 1937. They made clocks unti . . . | | | Yes |
| Hamilton | Hamilton Watch Company. Lancaster, Pennsylvania. Produced its first watch in 1893. | | | Yes |
| Gruen | Became known as Gruen Watch Company in 1922. | | | Yes |
| Golden Novelty Mfg. Co. | Made cast front cases that often housed Western Clock Clock Manufacturing Company or Western Clock Company movements. Chicago, Illinois. | | | Yes |
| Gilbert | William L. Gilbert was born in 1806 in Northfield, CT (a village of Litchfield) and became interested in the booming clockmaking business at Bristol in 1828. In that year he and his brother–in–law . . . | | | Yes |
| General Time Instruments Corporation | Holding company for Westclox and Seth Thomas 1936 - 1949. | General Time; Seth Thomas; Westclox | | No |
| General Time Corporation | Holding company for Westclox and Seth Thomas starting in 1949. | General Time; Seth Thomas; Westclox | | No |
| General Time | This is the base company for General Time Instruments Corp. and General Time Corp. | | General Time Corporation; General Time Instruments Corporation | Yes |
| General Electric Telechron | Name used in the mid-1950s on clocks. | Telechron | | No |
| General Electric | Part owner of Warren Telechron Company. Marketed clocks with the General Electric name. | Telechron | | No |
| Elgin | Made watches in the USA from 1864 to 1968. | | | Yes |
| Eico | Maker of electronic kits including hi-fi, stereo and test equipment. Electronic Instrument Company, Inc. 33 - 00 Northern Blvd., Long Island City 1, N.Y. Eico pioneered build-it-yourself kits for test . . . | | | Yes |
| E. Howard Watch Co. | Base company for E. Howard and Howard watches | | | Yes |
| Eastern Time Limited | Hong Kong, maker of clocks and movements for Westclox. Founded ca. 1964. | Westclox | | No |
| Dura Company | Toledo, Ohio, maker of cast cases such as the Westclox Dura Case models | | | Yes |
| Deemer Mfg. co. | Chicago, IL. Name on the back of the case iron stove clocks. | | | Yes |
| Columbia Time Products | A name Westclox used ca. the 1950s - 1960s on some private label or lower priced clocks. | Westclox | | No |
| Chelsea | Chelsea Clock Company. Founded in 1884 as Boston Clock Company, became Chelsea in 1897. Well known for ship's bell clocks. Still making clocks in the USA. | | | Yes |
