As the nation moved from World War II to a peacetime economy, industry sought the removal of wartime price and production controls. Labor, freed from a freeze on pay and a ban on strikes, sought wage increases averaging 30 percent. Strikes broke out like a contagion. Within a year, five million workers were involved in work stoppages.
In May 1946, 400,000 soft-coal miners went on strike. By mid-May the strike was crippling industrial production. The government responded by seizing control of the mines and negotiated an agreement for increased wages and other benefits. The workers returned to the mines. Nonetheless, six months later United Mine Workers leader John L. Lewis announced the agreement would end in five days after the Secretary of the Interior refused to reopen the contract.