Coal was so abundant in Britain that the supply could be stepped up to meet the rapidly rising demand. In 1700 the annual output of coal was just under 3 million tons. Between 1770 and 1780 the annual output of coal was some 6¼ million long tons (or about the output of a week and a half in the 20th century). After 1790 output soared, reaching 16 million long tons by 1815 at the height of the Napoleonic War. By 1830 this had risen to over 30 million tons The miners, less affected by imported labour or machines than were the cotton mill workers, had begun to form trade unions and fight their grim battle for wages against the coal owners and royalty-lessees.