Claim: In 1907, the union with the most members was Lanarkshire Miners' Federation, which represented coal miners in the Lanarkshire district of Scotland and was founded in 1893, and the second union with the most members was Fife and Kinross Miners' Association, which is a coal miners' trade union based in Fife and Kinross-shire in Scotland founded in 1869.
Evidence: The Lanarkshire Miners' County Union, later the Lanarkshire Mineworkers' Union, represented coal miners in the Lanarkshire district of Scotland. The union was founded in 1893 as the Lanarkshire Miners' Federation, bringing together local miners' unions based in Bellshill, Blantyre, Hamilton, Larkhall, and elsewhere. The Fife and Kinross Miners' Association was a coal miners' trade union based in Fife and Kinross-shire in Scotland. The union was founded in 1869 or 1870, and proved immediately successful by achieving the eight-hour day for miners in the counties, and was the first union to be recognised by Scottish mine owners. Lanarkshire Miners' Federation 34,000 Fife and Kinross Miners' Association 15,500