Early career Slattery was ordained to the diaconate in 1894 and to the priesthood in 1895. Because Groton, curiously, also served as the local parish church at the time, his teaching post allowed him to obtain his first experience as a parish priest at Groton's satellite church, St. Andrew's of
Ayer, Massachusetts.
Grace Church In 1910, Slattery became the rector of
Grace Church in
Manhattan, New York. At the time, Grace Church was one of the richest and most influential parish churches in the Episcopal Church; when Slattery left New York in 1922, he was the second-highest-paid Episcopal minister in the United States. An active parish priest, Slattery reportedly wrote over 2,500 personal notes to his parishioners a year. an organization that supported the Broad Church tendency within the Episcopal Church. He continued his ecumenical outreach to other Protestant denominations, such as Presbyterians, Methodists, Baptists, and Lutherans. In 1919, Slattery applied for the position of
Bishop of New York, but lost the election to
Charles Sumner Burch. Ironically, Burch died just one year later; Slattery performed the burial rites at his funeral. He applied for the episcopate a second time after Burch's death, but once again lost the election, this time to
William T. Manning, the conservative
High Church rector of
Trinity Church in Manhattan. In a narrow contest, he lost the clergy vote 126-109 and the lay vote 75–64. Certain electors suggested that Slattery lost because
William Randolph Hearst's newspapers attacked the England-born Manning for not being American enough, angering the electorate and causing them to back Manning out of spite.
The 1928 Book of Common Prayer In 1922, following the death of
Cortlandt Whitehead, Slattery became the chairman of the Episcopal Church commission tasked with revising the 1892 Book of Common Prayer, which had changed "little of substance" from the
1789 edition, and whose liturgy and catechism were considered theologically conservative. The commission had been operating since the 1913 General Convention, but successive General Conventions had repeatedly rejected and/or stalled most of its proposed revisions. According to Henry Washburn, dean of the Episcopal Theological School, "[t]o Slattery, more than to any one else, the general features of the revision are due." The commission's proposed revisions to the 1892 BCP were highly contentious among theologians. When the commission was convened, it was instructed to refuse to "consider or report[]" any "proposition involving the Faith and Doctrine of the Church." However, it "took this charge rather loosely." Although Slattery rejected the label of "liberal," he took the modernist side of the
Fundamentalist-Modernist Controversy; shortly before publishing the 1928 BCP, he declared that the Episcopal Church has "no fundamentalists in the sense in which that word is used to-day." The commission's revisions made "far-reaching, and in some instances radical," changes to both language and theology, decisively moving away from the concept of
total depravity. Slattery explained that he wanted to "substitute[] New Testament trust for Old Testament fear" and to recognize modern "aspirations ... for social justice, good government, and world brotherhood." Examples of the 1928 BCP changes include: • Removed
the word "obey" from the bride's portion of the marriage service (the groom had never been required to say this) • Provided priests with flexibility to adjust the liturgy, including "many opportunities for shortening the Services" (as Slattery himself put it) • Simplified the language of the Episcopal catechism to make it understandable to children
Diocese of Massachusetts Bishop Manning was only 55 years old at the time of his elevation, and served for another twenty-five years. With no future prospects for advancement in New York, Slattery returned to Massachusetts in 1922 as the
coadjutor bishop of the
Episcopal Diocese of Massachusetts, a title that, in Episcopal Church parlance, ensured he would become the Bishop of Massachusetts as soon as
William Lawrence retired. In 1923, he married Sarah Lawrence, the founder of the
Junior League of Boston; coincidentally, she was also Bishop Lawrence's daughter. He served until his death from a heart attack in 1930. == Other ==