In 1803 he married Emiah, the daughter of Welsh farmer. She died on 3 January 1805, aged 28. Following the loss of his wife in 1805 he secluded himself for seven years. In 1811 his successor at Broad Street, Thomas Finch, was dismissed for anti-Calvinistic heresy, and Richards interested himself in the erection of a new building, Salem Chapel, opened (1811) on General Baptist principles, but he rarely preached there. The congregation became Unitarian, and later dispersed. On 6 September 1818 Richards was admitted LL.D. by Brown University, but did not live to be aware of the honour. He died at Lynn on 13 September 1818 of angina pectoris, and was buried alongside his wife in the General Baptist Burial Ground at Wisbech. He bequeathed his library of 1300 volumes to Brown University, and left the rest of his property to his sister, Martha Evans. The History of Lynn In 1812 Richards published his best-known work, The History of Lynn, Civil, Ecclesiastical, Political, Commercial, Biographical, Municipal, and Military, from the earliest accounts to the present time … to which is prefixed … an introductory account of Marshland, Wisbech, and the Fens. It was published in the town, in two volumes, illustrated with aquatints after drawings by the Norfolk artist James Sillett. It tells the story of Lynn from Anglo-Saxon times until 1812, and the work is supplemented by biographical sketches, and by topographical and statistical information, with accounts of the religious houses formerly in Lynn, and of the progress of dissenting religion in the town. The collections of Guybon Goddard (d. 1677), the brother-in-law of Sir William Dugdale, freely used by Richards's predecessor, Benjamin Mackerell in his History of King's Lynn (1738), and by Charles Parkin in his Topography of Freebridge Hundred and Half, had been lost before Richards began writing, and he was denied free access to municipal records, so that his materials for the mediæval history of the town were limited. Other publications In addition to pamphlets and single sermons, Richards also published Review of Mr. Carter's Strictures on Infant Baptism (Lynn, 1781). Observations on Infant Sprinkling (Lynn, 1781). The History of Antichrist, or Free Thoughts on the Corruptions of Christianity (Lynn, 1784; published in Welsh, as Llun Anghrist, Carmarthen, 1790) These three publications were in controversy with John Carter, independent minister of Mattishall, Norfolk). Review of the Memoirs of the Protectorial House of Cromwell, by the Rev.