Why were early trade unions prosecuted under conspiracy and restraint-of-trade laws?

Early trade unions were frequently prosecuted under conspiracy and restraint-of-trade laws because governments and employers viewed the collective organization of workers as a threat to economic and political stability. During the 18th and 19th centuries, authorities often interpreted the act of workers combining to negotiate wages or working conditions as an illegal interference with the free market and individual liberty.12

In Great Britain, the Combination Acts of 1799 and 1800 explicitly criminalized trade unionism, subjecting workers to imprisonment for attempting to increase wages or decrease hours. Similarly, in the United States, courts initially applied common-law doctrines of criminal conspiracy to prosecute unions for attempting to establish closed shops or engage in collective action.231

These prosecutions were rooted in the belief that such combinations were intended to accomplish unlawful purposes or use unlawful means of coercion. It was not until landmark legal shifts—such as the 1842 ruling in Commonwealth v. Hunt in the U.S. and the Trade-Union Act of 1871 in Britain—that the legal status of unions began to be recognized as legitimate.31