The UMW was founded in Columbus, Ohio, on January 22, 1890, with the merger of two old labor groups, the Knights of Labor Trade Assembly No. 135 and the National Progressive Miners Union.[3] Adopting the model of the American Federation of Labor (AFL), the union was initially established as a three-pronged labor tool: to develop mine safety; to improve mine workers' independence from the mine owners and the company store; and to provide miners with collective bargaining power. After passage of the National Recovery Act in 1933, organizers spread throughout the United States to organize all coal miners into labor unions.
http://en.wikipedia.org/wiki/United_Mine_Workers_of_America
