First Congregational Church of Plymouth, CT. clock by Eli Terry, manufacturing pioneer

 
In 1807 Eli Terry signed a contract with the Porter Brothers of Waterbury, CT,  to produce 4000, wooden.\, shelf clocks in three years. Everyone said it was impossible. The best clock-makers would struggle to make a dozen clocks in a year. Terry met his obligation to make 4000 in three years for the Porters by developing the first mass production methods and machinery. Parts would be completely interchangeable without further filing and itting. Some consider Terry's accomplishment the most important step toward modern mass production.