He introduced mass production to the art of clockmaking, which made clocks affordable for the average American citizen.

Terry's apprenticeship to Burnap ended in 1792, and he quickly established himself as both a clockmaker and a repairer of watches in East Windsor.

Terry boarded girls like Candace Roberts to work in his shop painting clock dials.

And Terry was one of a number of Connecticut clockmakers who began to substitute water-powered machines for apprentices in the production of these rough-cut wheels.

In 1802 or 1803, Terry purchased a mill to produce wooden clock wheels, which still had to be finished by hand by skilled journeymen clockmakers.

He purchased a grain mill and used the water wheel and main shaft to run saws and lathes, which helped speed the production of parts.

Using his own ingenuity and inventiveness, Terry was thus able to speedily cut wheels, pinions, and other important clock parts accurately and repetitively.

In the year 1806, Terry signed the Porter contract to produce 4,000 wooden clock movements (other shops would make the cases).

According to historian Diana Muir writing in Reflections in Bullough's Pond, at that time a skilled craftsman could produce six to ten clocks per year.

He sold his manufactory to two of his assistants Seth Thomas and Silas Hoadley and retreated to his workshop to create the first machine in the world to be mass-produced using interchangeable parts.

In his autobiography, History of the American Clock Business for the Past Sixty Years and Life of Chauncey Jerome, Terry's employee and assistant Chauncey Jerome, later a great clockmaker and owner of the world's largest clock factory, mentions building the first pillar and scroll in Terry's workshop with the master's design and under his direction.

According to Diana Muir in Reflections in Bullough's Pond, within a few years, several hundred men worked in two dozen factories in the Naugatuck Valley and Bristol produced virtually identical Terry-style thirty-hour wooden clocks.

As noted Terry was granted many patents for his advances in clockmaking, most of which were immediately infringed upon by local competitors eager to participate in satisfying the demand for an affordable clock.

Terry also produced wooden-movement tower clocks, such as those found in the steeples of churches and meeting houses, one of which is still operational today in the town of Plymouth.

[5] Between 1808 and 1833, Terry focused the majority of his time and effort on the production of standardized wooden clocks, which helped him accumulate a modest fortune.

[7] Eli Terry's success in mass-producing and selling an affordable shelf clock for the public provided much inspiration to other entrepreneurs in Connecticut and beyond.

Immediately, Terry's former partners Seth Thomas and Silas Hoadley began making similar clocks.

In 1826-7, Eli Terry filed a lawsuit in Litchfield district court against Seth Thomas for patent infringement.

Contemporary historians believe the suit was staged between the two principals in order to dissuade others from competition, but it is unclear that this is correct since Terry, unlike Thomas, was the least interested in the business side of mass clock production.