emigrated to America in August 1793, and he expected to follow them. His wife was 'more bent on' it than himself (Memoirs, ii. 210). He resigned his charge on 21 Feb. 1794, preached a farewell sermon on 30 March, and embarked in the Sansom, off Gravesend, on 7 April. On 4 June he landed at New York, where Mrs. Priestley 'never felt herself more at home in her life.' He received a number of addresses. His answer to a blatant address of the 'Democratic Society' of New York 'pleased everybody except the society itself.' In reply to one from 'republican natives of Great Britain,' he declared his preference for a republic, and his hope of the abolition of slavery. He was disappointed at having no invitation to preach.
His sons and his friend Thomas Cooper, M.D. [q. v.], were interested in a proposed settlement in Pennsylvania on the Susquehanna. To be near them he left New York on 18 June, stayed a fortnight at Philadelphia, and on 11 July reached Northumberland, Pennsylvania. The settlement scheme was abandoned, but finding Northumberland a 'delightful situation' he made it his home, and built a house. He once preached in the presbyterian meeting-house, but the invitation was not repeated. Accordingly he held public services in his own house, and from about 1799 in a wooden building adjoining. A projected college came to nothing, though a building was begun. He had declined (November 1794) a chemistry chair at Philadelphia, than which he 'never saw a town' he liked less. But he resolved to spend two months there every winter, in hope of founding a Unitarian congregation. His discourses on the evidences, delivered there (February-May 1796) in Elhanan Winchester's universalist meeting-house, drew distinguished congregations, and a small Unitarian society was formed. On subsequent visits he attracted less attention ; his voice was very weak, and his teeth were gone. The deaths of his youngest son Henry (1795) and of his wife (1796) left him lonely, and the unfilial conduct of his second son, which his biographers pass in silence, affected him deeply. To his friend Lindsey he writes, on 29 Oct. 1796, 'Could I pay you one visit in England, I should sing my mine dimittis.' Henceforth he lived in the family of his eldest son.
In America his theology advanced to its final point by his adoption of a doctrine of 'universal restitution,' which he reached more slowly and with greater hesitation than was his wont. With the old universalist opinion, limiting retribution to this life, he had no sympathy; he looked for a moral progression to succeed the sleep of death. Thus on the death of his youngest son (1795) in his nineteenth year, he hopes that he 'had the foundation of something in his character on which a good superstructure may be raised hereafter.' Before 1803 this theory had established itself in his mind as a 'firm faith.' With this exception his American period shows industry in old directions rather than fresh activity of mind. To the American Philosophical Society at Philadelphia he communicated the results of new experiments. He wrote against Paine and Volney and a number of French freethinkers, upheld the biblical institutions in comparison with those of oriental antiquity, completed his church history, contrasted Socrates with our Lord, and annotated the whole Bible. His friends continued to contribute to his resources ; Mrs. Rayner sent him 50/. a year and left him 2,000/. ; the Duke of Grafton sent him 40/. a year.
He was never naturalised as an American citizen. In American politics he sided with the democrats against the federalists, which exposed him to the attacks of William Cobbett [q. v.] He corresponded occasionally with Adams, more with Jefferson. Throughout 1800 he had serious thoughts of returning to Europe ; by 13 Nov. he had made up his mind to sail for France (where he had property) as soon as there was 'free and safe communication.' But on 8 March 1801, while visiting Philadelphia, he was attacked by a bilious fever and pleurisy, which nearly cost him his life, and left him permanently enfeebled. He ceased to dig his garden, and was less in his laboratory, living much among his books. He was sounded (1803) about accepting the principalship of the university of Pennsylvania, but declined the overture. In May 1803 his left leg was lamed by a fall; soon after this his digestive powers, failed. Till the close of that year he was the first to rise in the morning, always lighting his own fire. At the end of January 1804 news reached London that he had suffered a loss of 200/. a year by the withdrawal of Wilkinson's aid. His English friends met on 6 Feb. (the day of his death) and raised an annual subscription of nearly 400. On 2 Feb. he made the last entry in his diary. Less than an hour before his death he dictated, with great precision, some emendations for a posthumous publication, adding, 'I have now done.'
He died at Northumberland on 6 Feb. 1804, and was buried in the quakers' burialground there on 9 Feb., William Christie [q. v.] giving a funeral address. His wife had died at Northumberland on 17 Sept.