Seabrease was a highly experienced priest, formal and somewhat aristocratic in his bearing. He had a strong baritone voice and preached impressively. However, he seems to have sought a lower profile for the church in the local press than that of his more outspoken predecessor, William Webbe. He believed strongly in committees to help administer the parish, and while staffed only by men, these committees took charge of various aspects of the parish, including finance, building and grounds, pews (which were still rented), and music.
Upon his arrival Seabrease found the vestry actively preparing plans to construct a new classroom building and rectory. He and his family had to rent a house initially while construction was underway, Prior to this time, the church had no classrooms for Sunday school and no place to hold church socials, requiring the renting of local halls for that purpose. The new buildings, designed by architects John F. Wing and Marshall S. Mahurin, included a Romanesque style house connected to the church by a classroom building, called the Parish House, all built in matching sandstone to the church. The Hall would contain three classrooms, an assembly hall, and a dining room. The rector and his family moved into the rectory in February 1890, but the women of the parish were immediately displeased with the design of the Parish House, which contained no kitchen facilities for the preparation of meals. Representing the Ladies Association, Georgiana (Wright) Bond, wife of vestryman Charles Ewing Bond, met with the vestry and demanded that a kitchen be provided or the women would "decline to work in the old way." She suggested that the parish borrow $1,000 to build an extension that would include a larger dining room and kitchen. The kitchen, which was constructed ultimately in the basement, provided some space for cooking but was considered by generations of parish women to be inferior.
Between 1891 and 1893, the vestry under Seabrease's leadership hired the firm of J. and R. Lamb of New York to redecorate the nave. A reredos with a painting of Jesus as the Good Shepherd arrived in 1891 as a memorial to the late Rev. Joseph large, and a new, highly-elaborate pulpit had arrived two years later, a gift from famed Kansas City Star editor William Rockhill Nelson as a memorial to his parents. Under the Lamb Company, the walls of the nave were painted with extensive gilding and stenciling, and an Alpha-Omega symbol in gilded letters was painted at the top of the chancel arch. Many members of the old lay leadership that had dominated the vestry for its first 50 years - Bailey, Nelson, Randall - passed away in the 1890s, bringing a new generation of leadership that would continue into the next century.
One of Seabrease's great accomplishments was the continued professionalization of Trinity's music program. A series of organists were hired, and a full-sized vested choir of men and boys made its appearance in 1892, dominating the parish's musical offering for the next generation. While many organists came and went, the English musical tradition set by the choir won notice in the city. Many boys who sang in its ranks did so for small pay and were not members of the parish.
Bishop Knickerbacker died unexpectedly at the end of 1894, and his successor, Bishop John Hazen White, was a less effective leader. White nonetheless successfully led an effort to divide the Diocese of Indiana, and a new diocese was created in its upper third that included Fort Wayne. It would be called the Diocese of Michigan City, and it was created at the end of 1898. Seabrease assumed a leadership role in the new diocese and filled several diocesan offices.
Mrs. Seabrease died in 1901, and through the efforts of an irascible new senior warden, William Ewing Hood, Seabrease was himself forced to resign three years later. His departure brought division within the parish, which Bishop White hoped to heal by promoting the skills of a new, younger rector, who would successfully take the reins of the parish. Seabrease moved to Wilmington, North Carolina, to live with his daughter, and he died there on 30 July 1921. His body was returned to Fort Wayne for burial. His children presented the parish with a handsome silver chalice and ciborium as memorials that are still used every Sunday.