Final answer:
The American Railway Union was winning the Pullman strike until the federal government sent troops to enforce an end to the strike. This interference crushed the union's efforts and led to the arrest of Eugene Debs.
Step-by-step explanation:
The American Railway Union was winning the Pullman strike of 1894 until the federal government interfered. Seeking to end the nationwide train stoppage and ensure the delivery of the U.S. mail during this critical economic period, the federal authorities ordered the strike to cease. President Grover Cleveland's administration sent federal troops to enforce this decree, resulting in clashes with striking workers and effectively breaking the strike.
Despite Eugene Debs and the American Railway Union's efforts to support the striking Pullman workers by boycotting trains with Pullman cars, the federal government's intervention crushed the strike. Eugene Debs was subsequently arrested for defying the court’s injunction against the strike, reflecting the government's commitment to maintaining operations of the nation's railroads.