Arkwright was a wig-maker from Preston with a gift for systems. He had patented a water-powered spinning machine, the water frame, in 1769, and he needed a stream powerful and reliable enough to drive it day and night. The Bonsall Brook and the Cromford Sough, an old lead-mine drainage channel, met at a point where a small valley folded into the Derwent. The water never froze; the sough kept flowing in dry summers; the village was poor and short of work. Arkwright bought rights to the water, built his mill, and then did the harder thing. He built the workforce. Because the local farming families would not enter the mill, he constructed cottages on North Street, schools, shops, pubs and a chapel. He invited entire families to settle. The factory was new. The factory town was new. Cromford was the prototype for both.

The discipline of the closed gate spread faster than the machinery. Within a generation, mills from Lancashire to Saxony to Pawtucket, Rhode Island, were running on Arkwright's pattern. Samuel Slater, who had been apprenticed to Arkwright's partner Jedediah Strutt, emigrated to America with the system carried in his head and founded the United States cotton industry on Cromford lines. Arkwright's water frame patent was eventually overturned for lack of originality, but it didn't matter. The bigger invention was the social one. When Arkwright died in 1792 he was the wealthiest untitled person in Britain. He had not just made a machine. He had made the working day as we still mostly know it, with its bells and shifts and lost pay for being late.

By 1801 the Napoleonic Wars had drained silver coinage from Britain, and small employers struggled to pay wages in legal tender. At Cromford, Arkwright's son ordered Spanish silver dollars to be overstamped with the figures '4s 9d' and circulated to the workforce. The coins, now called Cromford dollars, are extraordinary objects: Spanish reales bearing the head of Charles IV, stamped by an English mill, used to buy bread from a shop owned by the same family who owned the mill that paid for the bread. A few have survived. They sit in display cases at Derby Museum, small silver hieroglyphs of the closed economic loop that early industrial villages depended on.

Cotton spinning ended at Cromford around 1847 after Arkwright's son lost a landmark water-rights court case to a competing sough. The mill became a dyeing plant, then a colour-pigment works, then a derelict shell. Some of the buildings were lowered by two storeys. The 1775 mill burnt down in 1890. By the 1990s the site was a chemical waste hazard with a toxic tank covering the original waterwheel chamber. The Arkwright Society bought it in 1979 and began the slow work of cleaning it up. In 2001 the Derwent Valley Mills, including Cromford, were inscribed as a UNESCO World Heritage Site. In 2013 a working replica of an Arkwright water frame was installed. Finding suitable cotton roving for it proved a problem: no one spins cotton in Britain anymore, and the eventual supplier was a Swiss firm with experimental stock.

Cromford Mill is now open to the public every day. The eighteenth-century weavers' cottages still line North Street, with their characteristic three-storey loomshop windows on the top floor. The Cromford Canal towpath runs south from the mill yard to High Peak Junction, where you can see the surviving engine houses of one of the world's earliest railway inclines. The canal itself is a Site of Special Scientific Interest, full of dragonflies and herons. In 2024 the BBC filmed Antiques Roadshow in the mill courtyard, which seemed fitting: the building that invented industrial mass production hosting a programme about objects we now value because they were not industrially mass produced. A 20-kilowatt hydro-turbine is being installed in the old wheel chamber, restoring water power to the place where water power industrialised the world.