United States labor law
Since the Civil Rights Act of 1964, all employing entities and labor unions have a duty to treat employees equally, without discrimination based on "race, color, religion, sex, or national origin." There are separate rules for sex discrimination in pay under the Equal Pay Act of 1963. Additional groups with "protected status" were added by the Age Discrimination in Employment Act of 1967 and the Americans with Disabilities Act of 1990. There is no federal law banning all sexual orientation or identity discrimination, but 22 states had passed laws by 2016. These equality laws generally prevent discrimination in hiring, terms of employment, and make discharge because of a protected characteristic unlawful. There is no federal law against unjust discharge, and most states also have no law with full protection against wrongful termination of employment. Collective agreements made by labor unions and some individual contracts require people are only discharged for a "just cause". The Worker Adjustment and Retraining Notification Act of 1988 requires employing entities give 60 days notice if more than 50 or one third of the workforce may lose their jobs. Federal law has aimed to reach full employment through monetary policy and spending on infrastructure. Trade policy has attempted to put labor rights in international agreements, to ensure open markets in a global economy do not undermine fair and full employment.
Communications Workers of America v. Beck
In the United States, unions established the closed shop, union shop, and agency shop since at least the 1880s. The National Labor Relations Act (NLRA), the primary federal law governing labor relations in the United States, was enacted in 1935 and formally legalized the closed shop, union shop, or agency shop. In 1947, however, Congress enacted the Taft-Hartley Act, which amended the NLRA. Title I, Section 101 of the Taft-Hartley Act added a new Section 14 to the NLRA, part (b) of which banned the closed shop:
Nothing in this Act shall be construed as authorizing the execution or application of agreements requiring membership in a labor organization as a condition of employment in any State or Territory in which such execution or application is prohibited by State or Territorial law.
The Taft-Haftley Act did not, however, outlaw the union shop or agency shop (although it did place some procedural restrictions on their establishment and use).