In 1793 was published Jeremy Belknap's biography of Samuel Watts, who was an Arian, or, at least, held to the subordinate nature of Christ. This book had a very considerable influence in directing attention to the doctrine of the Trinity, and in inducing inquiring men to study the subject critically for themselves. In 1797 Dr. Belknap became the minister of the Federal Street Church in Boston, and his preaching was from that time distinctly Unitarian. Dr. Joseph Priestley removed to Philadelphia in 1794, and he was at first listened to by large congregations. His humanitarian theology--that is, his denial of divinity as well as deity to Christ--probably had the effect of limiting the interest in his teachings. However, a small congregation was established in Philadelphia in 1796, formed mostly of English Unitarians. A congregation was gathered at Northumberland in 1794, to which place Priestley removed in that year.
In the year 1800 a division took place in the church at Plymouth, owing to the growth there of liberal sentiments. These began to manifest themselves as early as 1742, as a reaction from the intense revivalism of that Period.[59] Rev. Chandler Bobbins, who was strictly Calvinistic in his theology, was the minister from 1760 until his death in 1799. In 1794 a considerable number of persons in the parish discussed the desirability of organizing another church, in order to secure more liberal preaching. It was recognized that Mr. Robbins was an old man, that he was very much beloved, and that in a few years the opportunity desired would be presented without needless agitation; and the effort was therefore deferred. In November, 1799, at a meeting held for the election of a new pastor, twenty-three members of the church were in favor of Rev. James Kendall, the only candidate, while fifteen were in opposition. When the parish voted, two hundred and fifty-three favored Mr. Kendall, and fifteen were opposed. In September, 1800, the conservative minority, numbering eighteen males and thirty-five females, withdrew; and two years later they organized the society now called the Church of the Pilgrimage. The settlement of Mr. Kendall, a pronounced Arminian,[60] was an instance of the almost complete abandonment of Calvinism on the part of a congregation, in opposition to the preaching from the pulpit. In spite of the strict confession of faith which Dr. Robbins had persuaded the church to adopt, the parish outgrew the old teachings. Mr. Kendall, with the approval of his church, soon grew into a Unitarian; and it was fitting that the church of the Mayflower, the church of Robinson and Brewster, should lead the way in this advance.