a place underground where coal is dug Culturecoal miningCoal was very important in the economic development of Britain. It was used as fuel in the factories built during the Industrial Revolution and continued to be important until the 1980s. The main coalfields (= areas where coal is mined) were in north-east England, the north Midlands and the valleys of South Wales, especially the Rhondda Valley. Towns and villages grew around the collieries or pits (= coal mines) and were dominated by the pithead where the lifting machinery was, and by large black slag heaps (= piles of waste material). Poor conditions and low pay led to a long history of industrial trouble and caused miners to play a leading role in the development of the trade union movement.In 1913 Britain produced 292 million tons of coal and employed over a million miners. In 1947, when the mines were nationalized (= brought under government control), there were still about 1 000 collieries and 700 000 miners. Increased use of North Sea oil and gas in the 1970s led to a lower demand for coal. Coal gas was replaced by natural gas. By the mid 1980s there were only 160 collieries and 200 000 miners. Fear of further job losses led to the long and violent miners' strike of 1984–5. In the 1990s there were more pit closures. In mining communities throughout Britain thousands of former miners have struggled to find new jobs. Collieries were returned to private ownership in 1994, and most coal now produced in Britain is sold to the electricity-generating industry. By 2003 no more than 11 000 people were employed in mining, and this number has grown smaller since then.Coal mining is important in the US, with the US producing a large part of the world's coal. Most is mined in the Appalachian Mountains. Modern mining techniques used in West Virginia have removed whole mountain tops and destroyed large areas of forest. Coal is used especially in the electricity-generating industry and in the manufacture of steel.