Inventors · 1772 – 1859
Eli Terry and Seth Thomas
Eli Terry (1772–1852) and his former assistant Seth Thomas (1785–1859) turned clocks from luxury items into something almost every American home could afford, by making them in large numbers from interchangeable parts in Connecticut.
Key facts
| Where | Connecticut, United States |
|---|---|
| Eli Terry | 1772 – 1852 |
| Seth Thomas | 1785 – 1859 |
| Turning point | The 1806 Porter contract for 4,000 clock movements |
| Legacy | The town of Thomaston, Connecticut, is named after Seth Thomas |
4,000 clocks at once
In 1806 Eli Terry signed a contract to make 4,000 wooden clock movements in about three years, a number nobody had attempted. Clockmakers normally built one clock at a time by hand. Terry set up water-powered machinery to cut parts that were identical and interchangeable, and he delivered. It was one of the earliest examples of mass production in America, years before it became famous in the gun and car industries.
He followed it with the pillar-and-scroll shelf clock, a small, cheap, handsome clock that sat on a mantel instead of standing on the floor. It sold in huge numbers.
Seth Thomas and his town
Terry's former assistants Seth Thomas and Silas Hoadley took over his old factory and began making clocks of their own. Seth Thomas built one of the most successful clock companies in the country, famous for shelf clocks, wall clocks and big tower clocks. In 1875 the village of Plymouth Hollow, where his factory stood, was renamed Thomaston in his honor. The Seth Thomas company also patented a wind-up bedside alarm clock in 1876.
Read more: The mechanical clock (history chapter) · the full story of the watchmakers
Questions people ask
Who mass-produced clocks first in America?
Eli Terry, starting with a contract signed in 1806 to make 4,000 clock movements from interchangeable parts.
Is the Seth Thomas clock company still around?
The name survives as a brand, but the original Connecticut manufacturing ended in the 20th century.
Sources
Last updated October 18, 2026. Found an error? Tell us.