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 .

The mining companies refused Agree_or_refuse_to_act to meet the demands Request of the workers and instead hired Employment Baldwin-Felts agents equipped Supply with high-powered rifles to guard Patrolling the mines and act as strikebreakers .

After an exchange Exchange of gunfire Use_firearm by armed Bearing_arms guards and union miners , three miners and 20 non-miners were killed Killing , including the superintendent and 19 strikebreakers .

Enraged that the owner had disregarded Agree_or_refuse_to_act their agreement Sign_agreement , on June 21 , union miners shot Use_firearm at strikebreakers going to Self_motion work Being_in_operation , where the mine had armed Bearing_arms guards .

The next day , union miners killed Killing superintendent McDowell and 18 of 50 strikebreakers and mine guards , many of them brutally .