John Beach, a former Newtown Congregational minister, converted to the Anglican Church in 1732, sailing to Scotland for his ordination and returning to become rector of what would become Trinity. A year after his death in 1782, the American Episcopal Church was formally established.
Trinity later became the largest parish in the Episcopal diocese and over time the church expanded. In 1870, the present stone church was built.
The church offers Sunday classes for children as well as youth programs and adult study groups. Worship is held four times on Sunday morning and less often during the summer.
The Trinity Day School is a private, nonprofit preschool that offers two and a half hour morning and afternoon sessions two or three times a week for 3- and 4-year-old children. A head teacher and teacher assistant is in every classroom. Three-year-olds have a class size of about 13 while 4-year-olds have a class size of 15.