Original sentence: In the 18th and 19th centuries, parts of Northamptonshire became industrialized.Later, Rockingham Castle was built for William the Conqueror and was used as a Royal fortress until Elizabethan times.Northampton and its surrounding areas gained a sizeable shoemaking and leather industry and by the end of the 19th century it was almost definitively the boot and shoe making capital of the world
Edited sentence: In the 18th and 19th centuries, parts of Northamptonshire and the surrounding  area became industrialized,.Rockingham Castle was built for William the Conqueror and was used as a Royal fortress until Elizabethan times.The local speciallisation was the shoemaking and leather industry and by the end of the 19th century it was almost definitively the boot and shoe making capital of the world