In 1844, two loggers discovered iron ore seams near their mill on the Great Village River. The site was visited by world-famous geologists who determined it would be economically viable to mine. A report in the British Parliament on 9 November 1847 noted that "charcoal iron made from these ores will rival the best made in Sweden" with ore consisting of iron levels as high as 70%. Acadia Charcoal Iron Co. began mining operations in 1849 along the bank of the Great Village River, from which grew the settlement of Acadia Mines (also known as Acadian Mines). The mine's workings included several open quarries, vertical and horizontal shafts – some as deep as 70 feet – a Catalan forge, a 35-foot-high blast furnace, and a large damn to generate power. In 1851, samples of their ore and pig iron were sent overseas for the manufacture of guns. Samples were also sent to the Great Exhibition in London, where they received first prize.
The pig iron the mine produced was transported by ox cart or horse to the nearby town of Great Village (previously known as the Port of Londonderry) and loaded on to ships. Once the railway was complete in 1858, ore was also shipped by train to Halifax. In 1869, the mine began manufacturing steel car wheels for the anticipated Intercolonial railway and produced steel used for drilling during its construction. When the Intercolonial railway line from Truro to Amherst opened in 1873, Acadia Mines prospered. In 1874, the mine was purchased by the Steel Company of Canada, who, over the next ten years, spent $2.5 million on expansion including adding a 63-foot-high blast furnace. In 1875, the mine established a second operation at East Mines. Population in the Acadia Mines settlement increased by 130 percent over the next ten years. It is estimated that during its peak, approximately 1200 workers were employed at the mine.
1876 was an exciting year for the mining operations as 67 experimental beehive-shaped coke ovens were added to the site to produce coke from coal. Tracks were laid across the top of the ovens, and small coal cars filled each oven through its "charging hole" on top. It took over 40 hours to produce coke from coal. By 1906, the mine had a total of 53 beehive ovens.
Water was very important to mining operations including both the blast furnace and coal wash. The Rockland River was damned to create a reservoir, from which a flume channelled water to the blast furnace. The edge of the river was also where white-hot slag was dumped. It was said that at night, the glow of the hot slag could be seen all the way down the Cobequid Bay.
As the mine's operations expanded, it began to manufacture several new products. A wire mill that produced fencing was added in 1887, and in 1888, a pipe foundry was constructed. Around this time, the company reorganized and was renamed the Londonderry Iron and Steel Co. Ltd. Historian Trueman Matheron noted that the company was “the only iron works in Canada with smelting, casting, and rolling, all under the same management.” The company's prosperity did not last long, however. By 1891, the iron ore was nearly exhausted, and the mine could no longer run the blast furnace. The company began to outsource ore form Torbrook, Annapolis County, but their ore contained too much phosphorous and produced low-quality iron by comparison. This impacted Londonderry's reputation for producing high-quality iron. Between their damaged reputation and the competitive price of imported iron, in 1898, the mine ceased operations. This did not discourage some investors, however, who reopened the mine in 1903, renaming it the Londonderry Iron and Mining Co. Everything except for the rolling mills resumed operations. The town also had a new name, which officially became Londonderry in 1902.
Unfortunately, Londonderry's rejuvenated mining operations were short-lived. In 1908, operations ceased for a second and final time. The effects of the mine's closure were felt throughout Colchester County and even the province. The town of Londonderry was the hardest hit as mine workers and their families moved away. In 1920, disaster struck: on a dry and windy spring day, a raging fire destroyed 54 buildings in the town. During its peak in the 1880s, Londonderry was a community of 5000 people. After the fire, the population decreased dramatically, eventually becoming a ghost town. The mine's iron works were sold for scrap in the 1920s and the rest was purchased and dismantled over the years. All that remains of Acadia Mines are some bricks from the coke ovens and the remnants of the “slag pit” by the Rockland River.