Final answer:
The workers at Carnegie's steel mills had to deal with the management's attempt to crush their union.
Step-by-step explanation:
The other serious problem that Carnegie's workers had to contend with at this time was the management's attempt to crush their union. In the spring of 1892, the workers' union contract was coming to an end and management reduced their pay. Anticipating a strike, management stockpiled finished steel in advance and hired the Pinkerton detective agency to escort strikebreakers into the factory. The workers armed themselves, seized control of the plant, and clashed with the Pinkertons, resulting in deaths. The strike was later crushed by federal troops and most of the surviving workers accepted the reduced pay and the elimination of their union.