In 1807 the Presbyterian divine John Mitchell Mason published A Plea for Catholic Communion in the Church of God, a vigorous attack on the doctrine of apostolic succession as it was held by the Episcopal Church. Hobart, then assistant minister of Trinity Church, New York, replied at length in An Apology for Apostolic Order and Its Advocates — a book that runs to several hundred pages, took the controversy out of the magazines and on to a more serious footing, and established Hobart as the foremost American defender of the Catholic understanding of episcopacy.
The Apology is, in form, a controversial book, and it bears the marks of its occasion. But it is also a remarkably patient piece of theological exposition. Hobart sets out from the scriptures, traces the doctrine of orders through the Fathers, weighs the Reformation settlements, and shows where the American Episcopal Church stands within the historical Church. He is firm without being shrill, and he is willing to grant his opponents what he can grant them: he does not believe Presbyterian ministers are no ministers at all, but he does believe that the apostolic order is an essential feature of the Church as Christ founded it.
The book had a long afterlife. It went through several editions in Hobart’s lifetime and continued to be reprinted into the second half of the nineteenth century. It influenced an entire generation of American High Churchmen, and the Tractarians who were to take up its themes in England a generation later were not unaware of it. It is, in many respects, the foundational doctrinal statement of American Anglicanism.