Harlan County, USA (1976)

Harlan County, USA is a 1976 Oscar-winning documentary film covering the "Brookside Strike", an effort of 180 coal miners and their wives against the Duke Power Company-owned Eastover Coal Company's Brookside Mine and Prep Plant in Harlan County, southeast Kentucky in 1973. Directed and produced by Barbara Kopple, who has long been an advocate of workers' rights, Harlan County, U.S.A. is less ambivalent in its attitude toward unions than her later American Dream, the account of the Hormel Foods strike in Austin, Minnesota in 1985-86.

More at Wikipedia.