Following the advice of the GMA, they prevailed upon the Los Angeles district attorney to request permission from U.S. attorney general Richard Olney to prosecute the strikers for conspiracy. Olney, a former railroad lawyer and GMA member, was pleased to grant permission. The companies then persuaded a friendly judge in Los Angeles to do two things. On June 29, he summoned a grand jury to determine whether the striking workers were guilty of conspiracy for obstructing mails and interstate commerce. And the following day he issued an injunction which directed workers to end the strike or resign.

Olney authorized sending federal troops to Los Angeles, despite the nearly complete lack of violence among the highly disciplined strikers. According to one of the soldiers, they were not enthusiastic at their assignment, “this idea of shooting down American citizens simply because they are on a strike for what they consider to be their rights. . . . All of the boys are against it from first to last, and many are in sympathy with the strikers.” The heavily armed troops were deployed to escort strikebreakers, run trains, and intimidate strikers.