In two years after he married Anne, third daughter of Felix Calvert, Esq. of Albury-Hall, in Hertfordshire, and the sister of John Calvert, Esq. one of his most intimate friends, who was returned to that and many successive Parliaments, for the borough of Hertford. "By this most excellent lady," says his biographer, with the amiable warmth of filial tenderness, "who was allowed to possess every endowment of person, and qualification of mind and disposition which could render her interesting and attractive in domestic life, and whom he justly regarded as the pattern of every virtue, and the source of all his happiness, he lived in uninterrupted and undiminished esteem and affection for nearly half a century; and by her (who for the happiness of her family is still living) he had thirteen children, of whom eight only survive him." This long period is little checquered with events. Having no taste for public business, and his circumstances being easy and independent, he passed the first fourteen years at his seat in Cambridgeshire, in an alternation of study and the recreations of rural life, in which he took much pleasure. But, at the end of that time, the loss of his sister gave a shock to his spirits, which they did not speedily recover. That she was a lady of superior talents is probable, from her having been admitted to a friendship and correspondence with Mrs. Montague, then Miss Robinson. The effect which this deprivation produced on him was such as to hasten the approach, and perhaps to aggravate the violence, of a bilious fever, for the cure of which by Doctor Heberden's advice, he visited Bath, and by the use of those waters was gradually restored to health. In 1766 he published his Bath Guide, from the press of Cambridge; a poem, which aiming at the popular follies of the day, and being written in a very lively and uncommon style, rapidly made its way to the favour of the public. At its first appearance, Gray, who was not easily pleased, in a letter to one of his friends observed, that it was the only thing in fashion, and that it was a new and original kind of humour. Soon after the publication of the second edition, he sold the copy-right for two hundred pounds to Dodsley, and gave the profits previously accruing from the work to the General Hospital at Bath. Dodsley, about ten years after his purchase, candidly owned that the sale had been more productive to him than that of any other book in which he had before been concerned; and with much liberality restored the copy-right to the author. In 1767 he wrote a short Elegy on the Death of the Marquis of Tavistock; and the Patriot, a Pindaric Epistle, intended to bring into discredit the practice of prize-fighting.