Reserves of copper were discovered in the Tamar Valley in the 19th century and the area in and around Milton Abbot became heavily industrialised. Eventually the copper ores were worked out but useful quantities of manganese remained and were mined here until the 1930s. Used in steel making and in cast iron production, manganese played an important part in the industrial expansion of the 19th and early 20th centuries.

Like the "Bal Maidens" of Cornwall, women worked the same long hours as the men at rough and did very dirty work.

Copper was also commercially mined in Devon at North Molton, Tavistock Hamlets and at Littleham near Budleigh Salterton.