An outstanding example of colonial masonry, the front section of St. John's was built first. The 1765 addition created the present T shape. A glistening Flemish bond appears above the water table and English bond below. The pedimented molded brick doorways are beautifully handled. The eight large windows, now lengthened, have semicircular arches with rubbed brick voussoirs. On the interior, the west and north galleries date from the enlargement. The reredos—13 feet, 3 inches wide—is the outstanding feature of the interior, but it probably is not original to the building since it does not fit into the space. Abandoned at disestablishment, the church was used by various groups. After the Civil War, the building was reconsecrated as an Episcopal church.