The United Mine Workers of America (UMW or UMWA) is a United States labor union that represents workers in mining. One of the groups in the forefront of the fight for collective bargaining in the early 20th century, the UMW was founded in Columbus, Ohio, on January 22, 1890, by the merger of two earlier groups, the Knights of Labor Trade Assembly No. 135 and the National Progressive Union of Miners and Mine Laborers. It was modeled after the American Federation of Labor (AFL).

After passage of the National Recovery Act in 1933, organizers spread out throughout the United States to organize all coal miners.

Achievements

• An eight-hour work day in 1898, collective bargaining rights in 1933, and safety protections in 1969.