An injunction is a court order instructing a party to do, or refrain from doing, a specified act.
Beginning in the 1880s, the injunction was requested by industrial management and granted by sympathetic courts to end strikes and boycotts. Its effectiveness was demonstrated during the Pullman Strike of 1894. The injunction long remained a prime tool used to curb labor union power.
In 1932, the Norris-La Guardia Act enumerated labor practices to be rendered exempt from judicial injunction, including the strike. In the wake of this law and other New Deal measures, many state legislatures enacted laws enhancing the powers of unions.
Following World War II, Congress passed the Taft-Hartley Act (1947), which allowed the courts to resume the use of injunctions under specified circumstances. The Labor Management Reporting and Disclosure Act (1959) further broadened the courts authority to issue injunctions.