[2] Miles married Catherine (1798–1869), daughter of John Gordon, on 12 September 1823, with whom he had the following children:- He was Tory Member of Parliament (MP) for Chippenham from 1818 to 1820, for New Romney from 1830 to 1832, and sat for East Somerset from 1834 to 1865 as a Conservative.
Sir William was a staunch Conservative, opposed to the Reform Act, and was a protectionist who favoured the Corn Law and supported the Duke of Richmond's Central Agricultural Protection Society (known as the "Anti-League").
"[6] He was deeply religious, at one stage putting forward an amendment in Parliament to prevent trains running on the then newly proposed Great Western Railway on Sundays.
When the parish church at Abbots Leigh burned down in 1847, he paid for its rebuilding from his own pocket.This afternoon while the bells were chiming for divine service, a fire broke out in the rafters of the roof on the north side of the Church, it was ascertained the next day that the fire was caused by a crack in the chimney of the Store which was most negligently & stupidly built of only one brick thick and placed in immediate contact with the wall plate upon which the feet of the rafters rested.
The fire, not withstanding the most active exertions of all the male inhabitants headed by William Miles Esq., whose exertions were almost incredible; the aid of the powerful engine from Leigh Court and after an interval of an hour and a half the assistance of three engines from Bristol, consumed the whole of the roof of the nave and south Aisle, the gallery, pulpit, reading desk and nearly all the pews leaving the tower and chancel uninjured.
A prominent agriculturalist and one of the founding fathers of the Royal Agricultural Society, he was chairman of the local committee who "contributed to the excellence of the arrangements" for the Bristol Country Meeting.
"[11]"A keen sportsman, he was a hard rider with Sir Richard Sutton, Bt, at Lincoln in his youth (see Burton Hunt),[12] an earnest politician, an able magistrate, an enlightened agriculturalist and a warm-hearted friend."