From age 14 Terry was apprenticed to clock maker Daniel Burnap. In 1793 Terry opened a business in the area that became known as Plymouth. He received the first clock patent granted by the United States Patent Office (1797), and about 1803 he devised ways to use waterpower to operate his machines. In 1807 he hired Seth Thomas (Thomas, Seth) and Silas Hoadley to carry out a contract to make 4,000 wooden clock movements for Edward Porter and Levi G. Porter. When this was completed in 1809, Terry went into semi-retirement, but he continued some business for himself. His specialty was then the manufacture of one-day wooden shelf clocks, designed in 1814 and patented two years later.