Thomas was born in Wolcott, Connecticut, in 1785. He was apprenticed as a carpenter and joiner, and worked building houses and barns. He started in the clock business in 1807, working for clockmaker Eli Terry. Thomas formed a clock-making partnership in Plymouth, Connecticut with Eli Terry and Silas Hoadley as Terry, Thomas & Hoadley.
In 1810, he bought Terry’s clock business, making tall clocks with wooden movements, though chose to sell his partnership in 1812, moving in 1813 to Plymouth Hollow, Connecticut, where he set up a factory to make metal-movement clocks. In 1817, he added shelf and mantel clocks. By the mid-1840s, he changed over to brass from wooden movements. He made the clock that is used in Fireman’s Hall. He died in 1859, whereupon the company was taken over by his son, Aaron, who added many styles and improvements after his father’s death.