Within fifty years, it became the richest individual copper mine in England producing over sixty thousands tons of ore. Until 1769, when the fifth Duke, William Cavendish, opened his own works at nearby Whiston in the Churnet Valley, the ore was carried to Denby by packhorse for smelting.

Much of the copper was used for making brass, but over three hundred tons was supplied to the Navy to protect the hulls of its ships against boring worms, after being rolled at the works of Thomas Evans in Derby.

[2] Arthur Ratcliffe MP built a house, modelled on a medieval castle, complete with battlements, next to the former lead mine in 1932.

The Express Dairies creamery at Ecton created most of the freight traffic on the Leek and Manifold Valley Light Railway line, with most of its product destined via dedicated milk trains for London.

After the First World War, the churns were loaded into standard-gauge vans taken to and from Ecton on the transporter wagons.