In 1953, when it became almost impossible to make boat and bus connections in order to attend St. Luke's Cathedral in Portland, Daniel Sullivan (a summer resident and the organist at St. Luke's who later became an Episcopal priest) offered a solution. He suggested that Bishop Oliver Loring be approached to inquire about the possibility of establishing a chapel for the summer months on Peaks Island. Not only did he enthusiastically support the proposal, but he also pledged financial support.
Since it was the Trinity season, it seemed appropriate to name the chapel Holy Trinity. Original members still in the congregation are Mary Ann Sanford, Barbara Whitney, Charlotte and Marty Patterson, and Mary and David Haeger.
The early years of the chapel were difficult since the chapel had no permanent clergy. Members had to rely on visiting priests who came from the mainland each Sunday morning. After a few years the congregation was able to rent a cottage on the island for the months of July and August in order to provide the visiting priest and family with a summer residence during their stay. Holy Trinity doesn't receive any financial support from the diocese and relies on its plate collections, fairs, and winter tithing to meet expenses.
Holy Trinity's first services were held at T.E.I.A. clubhouse. Although greatly appreciated, it was not always convenient because there were often conflicts. When members of St. Christopher's Roman Catholic Church invited members of the chapel to use their building, they gladly accepted. The congregation also held services at the Brackett United Methodist church at one time.