Mechanization and black migration ended industry’s reliance on European immigrant labor.

Evidence

In any event businessmen were discovering that the iron men, combined with growing migration of black men from the rural South, were emancipating industry from its historic dependence on European manpower. Business journals began to assure their readers that a permanent solution of the immigration problem had arrived. “Machinery,” one business editor wrote, “stays put.’ It does not go out on strike, it cannot decide to go to Europe, or take a job in the next town.” — John Higham, Strangers in the Land, 1904

Categorization

• XREF: Connects to the reader’s interest in how perceived threats (immigrant labor) can be replaced by substitutes; relevant to how groups adapt when a feared out-group becomes dispensable.