The Taft-Hartley Act is also known as the Labor-Management Relations Act of 1947. The Act allowed the president to intervene if he believed a strike would be detrimental to the nation's health or safety, according to History News Network.
The Taft-Hartley Act also prohibited some union activities, such as sympathy strikes, secondary boycotts and discrimination against non-union members. There was a provision that union officers had to file a non-communist affidavit and take an oath that they were not communists. This proved to be a contentious part of the law, says the History News Network. President Nixon was the last president to successfully invoke the Taft-Hartley Act in response to a longshoremen's strike.