In the late 1800s, the federal government (as well as most state and local governments) invariably took the side of management in dealing with large strikes.
In those days, the federal government and most mainstream thinkers were firmly opposed to labor unions. Unions were seen as a possibly illegal way to coerce employers into giving in to worker demands. They were also seen as subversive entities that might undermine the basic foundations of US democracy and capitalism. This was particularly so as more and more anarchists and other radicals came to join unions.
Therefore, the federal government took the side of employers, doing such things as issuing injunctions against strikes and even sending in troops to help break strikes up.
During the major strikes of the 1800s, the government viewed labor unions as impediments to the development of the economy and sided with the company owners. Unions were also seen as parallel bases of power and authority because of their influence among workers and their families. Thus, the government was always suspicious of their activities, and the situation during the strikes only served to confirm their fears.
For instance, during the Pullman strike, the railroad companies enlisted help from the federal government to break the strike led by the American Railway Union. The railway companies claimed that the striking workers were obstructing the delivery of the US Mail, which forced the government to seek an injunction against the union. The courts upheld the move by the government. The union leaders were arrested, and the strike ended in favor of the railway companies.