United States labor law: The U.S. Supreme Court rules in NLRB v. Fansteel Metallurgical Corp. that the National Labor Relations Board has no authority to force an employer to rehire workers who engage in sit-down strikes.

United States labor law sets the rights and duties for employees, labor unions, and employers in the US. Labor law's basic aim is to remedy the "inequality of bargaining power" between employees and employers, especially employers "organized in the corporate or other forms of ownership association". Over the 20th century, federal law created minimum social and economic rights, and encouraged state laws to go beyond the minimum to favor employees. The Fair Labor Standards Act of 1938 requires a federal minimum wage, currently $7.25 but higher in 29 states and D.C., and discourages working weeks over 40 hours through time-and-a-half overtime pay. There are no federal laws, and few state laws, requiring paid holidays or paid family leave. The Family and Medical Leave Act of 1993 creates a limited right to 12 weeks of unpaid leave in larger employers. There is no automatic right to an occupational pension beyond federally guaranteed Social Security, but the Employee Retirement Income Security Act of 1974 requires standards of prudent management and good governance if employers agree to provide pensions, health plans or other benefits. The Occupational Safety and Health Act of 1970 requires employees have a safe system of work.

The Supreme Court of the United States (SCOTUS) is the highest court in the federal judiciary of the United States. It has ultimate appellate jurisdiction over all U.S. federal court cases, and over state court cases that turn on questions of U.S. constitutional or federal law. It also has original jurisdiction over a narrow range of cases, specifically "all Cases affecting Ambassadors, other public Ministers and Consuls, and those in which a State shall be Party." In 1803, the court asserted itself the power of judicial review, the ability to invalidate a statute for violating a provision of the Constitution via the landmark case Marbury v. Madison. It is also able to strike down presidential directives for violating either the Constitution or statutory law.

National Labor Relations Board v. Fansteel Metallurgical Corporation, 306 U.S. 240 (1939), is a United States Supreme Court case on labor laws in which the Court held that the National Labor Relations Board had no authority to order an employer to reinstate workers fired after a sit-down strike, even if the employer's illegal actions triggered that strike.