The ancient parish covered a large area extending to the River Severn, and included the detached area of Rangeworthy until 1866, when this became a separate civil parish. In 1894 the western part was detached to form the civil parish of Oldbury-on-Severn and the eastern part to create that of Falfield. Thornbury Township, Pennsylvania, USA, founded in 1687, was named after Thornbury, Gloucestershire, by George Pearce, whose wife Ann came from there. In 1765 Dr John Fewster of Thornbury presented a paper to the Medical Society of London entitled “Cow Pox and its Ability to Prevent Smallpox”. Fewster was a big influence on his friend and colleague Edward Jenner, the pioneer of vaccination. Thornbury was once the terminus of a Midland Railway (later LMS) branch line from Yate on the Bristol to Gloucester main line, with intermediate stations at Iron Acton and Tytherington. It lost its passenger services in June 1944 but continued as a goods route, also serving quarries at Tytherington. The site of Thornbury railway station and the line have been redeveloped into a supermarket, a housing estate, a bypass road and a long footpath. Further relics of the line can be seen at Tytherington Quarry to the east of the town. There are plans to reopen the line to Yate via Tytherington and Iron Acton and possibly restore services to Gloucester and Bristol.