For five days from late August to early September 1921 , some 10,000 armed coal miners confronted Hostile_encounter 3,000 lawmen and strikebreakers ( called Name_conferral the Logan Defenders ) who were backed by coal mine operators during the miners ' attempt to unionize Becoming_a_member the southwestern West Virginia coalfields when tensions Hostile_encounter rose Cause_change_of_position_on_a_scale between workers and mine management .