In "The Devil in the White City," author Erik Larson describes Holmes as a harsh contractor who mistreated his workers. He would often berate them, regardless of the quality of their work, and refused to pay wages, leading to a high turnover rate. Many workers quit or were dismissed, allowing Holmes to continuously recruit new laborers.
This strategy, while slowing down construction, significantly reduced costs. The frequent replacement of workers also minimized the number of people privy to the secrets of the building, furthering Holmes's dubious agenda.