The National Labor Relations Act (NLRA), sometimes called the Wagner Act after its chief sponsor, Sen. Robert F. Wagner (D-N.Y.), is the principal federal law governing the operation and organizing of labor unions in the private sector and their relations with management representatives. Enacted in 1935 as part of President Franklin Roosevelt’s New Deal economic central planning programs, the law replaced the labor-management relations provisions of the National Industrial Recovery Act, which had been found unconstitutional by the Supreme Court.
The original NLRA was strongly supported by labor unions, as it guaranteed mandatory collective bargaining with a labor union organized under its provisions. The law additionally prohibited employer interference in organizing labor unions and prohibited retaliation against employees who went on strike. NLRA also established a quasi-judicial administrative body, the National Labor Relations Board, which would create a body of law expanding the NLRA’s application and implications for the U.S. economy.
The law’s passage led to an initial surge in union organizing and strike activity. Unionization in the labor force peaked shortly after the end of the Second World War; since that time it has declined substantially in the private sector. The NLRA applies to almost all employers in the private sector; government employees at all levels, agricultural workers, and the railroad and airline industry are covered by other labor relations laws.
Since its enactment, NLRA has been subject to three major amendment cycles. In 1947, the Labor Management Relations Act—better known as “Taft-Hartley” after its sponsors—removed certain labor union privileges, codified rules for collective bargaining, and expanded the NLRB’s jurisdiction over unfair labor practices by employers to unfair labor practices by labor unions. The 1959 Labor Management Reporting and Disclosure Act, passed in response to revelations of labor union corruption, amended the NLRA to ban striking against businesses not directly implicated in a labor dispute and establishing new legal rights for union members enforceable against their unions. In 1974, Congress passed technical amendments to NLRA modifying its application to the healthcare sector.
The National Labor Relations Act fundamentally restructured American labor law. Prior to 1935, collective bargaining was limited by court orders and rules allowing employers not to negotiate with unions and not to hire union members. The New Deal Democrats, closely aligned with labor unions in the American Federation of Labor (the forerunner of the modern AFL-CIO), sought to use the economic upheaval caused by the Great Depression and the collapse under legal scrutiny of the National Industrial Recovery Act (NIRA) to secure a wide-ranging collective bargaining law.
That law became the NLRA, known as the Wagner Act after its sponsor, liberal U.S. Senator Robert F. Wagner (D-N.Y.). The Wagner Act contained five principal provisions: prohibiting management to “interfere, restrain, or coerce” employees seeking to organize for mutual benefit; prohibiting management from interfering in the internal administration of labor organizations; prohibiting employers from discriminating against employees based on union membership or union support, including strike action; prohibiting management retaliation against employees who made formal labor complaints; and compelling employers to bargain collectively with labor unions. The Act also established a National Labor Relations Board (NLRB) to prosecute and adjudicate these provisions outside of the regular federal court system.
The NLRA, as amended, applies to the vast majority of private sector workplaces outside the agricultural, railroad, and airline industries. Collective bargaining in the railroad and airline industries is governed by the Railway Labor Act, a 1926 law passed as a compromise between labor and management interests in the railroad industry that was later extended to airlines. Due in part to the prominence of African Americans among farm laborers in the 1930s, agricultural workers were excluded from the NLRA: While some states (most prominently California) have extended collective bargaining laws to farmworkers, the federal government has not.
Labor unions had been disappointed by the collective bargaining provisions in NIRA. Employers were able to arrange management-controlled “company unions” where they did not flout the collective bargaining provisions entirely.
To ensure that organized labor would be able to compel management to bargain, the Wagner Act required employers to bargain collectively with any organization of the employees’ choosing—in practice, almost always a unit of a major national labor union. The Wagner Act stipulated that a union would be formed for a so-called “bargaining unit” of employees in a similar-enough class of jobs if a simple majority supported the union. Under NLRA procedures, the union can demand (and in practice always demands) “exclusive representation” or “monopoly bargaining,” compelling all members of the bargaining unit to be negotiated for by the union if the simple majority support threshold is met.
The Wagner Act also prevented employers from controlling or interfering in the unions of their company’s employees; the provision has been interpreted to prohibit not only captive “company unions” but almost all non-adversarial employer-employee labor relations arrangements, most notably German-style “works councils.”
The Wagner Act privileged striking, by guaranteeing the right of employees to “concerted activity” and protecting strikers from being fired. A court decision in 1938 gave employers the ability to hire replacement workers, but held that strikers must be reinstated if new positions opened after the strike ended.
Also see National Labor Relations Board (Government Agency)
The Wagner Act established a self-enforcement mechanism by creating the National Labor Relations Board (NLRB), an autonomous, quasi-judicial body tasked with prosecuting and judging violations of the Act, known as “unfair labor practices.” The NLRB also holds supervisory authority over union representation elections.
NLRB cases are first heard by any of a series of administrative law judges (ALJs), executive branch officials appointed by competitive examination who rule on cases. The ALJ decisions may be appealed to the five-member presidentially appointed board. By convention, the President’s political party is guaranteed a one-vote majority on the five-member final tribunal and control of the agency’s prosecutorial arm (the General Counsel), resulting in frequent reversals in applicable legal precedent.
In 1914, syndicate labor unionism—using anti-competitive practices to organize workers for mutual benefit—was legalized by the Clayton Act, which exempted labor unions from anti-trust laws. In 1926, to resolve strikes in the railroad industry, Congress enacted its first nationwide labor relations law, the Railway Labor Act, to govern collective bargaining in the railroad industry. After the financial crisis of 1929 initiated the Great Depression, public demands for a national labor union law surged. In 1932, Congress passed the Norris-LaGuardia Act, which prevented employers from adding provisions prohibiting labor union membership to employment contracts (also called “yellow dog” contract provisions) and restricted the use of court injunctions to end strikes.
With the election of President Franklin Roosevelt in 1933, labor unions—then organized as the American Federation of Labor (AFL)—sought to win a national collective bargaining law as part of the “New Deal” program of economic central planning Roosevelt promised. A collective bargaining provision was included in the National Industrial Recovery Act (NIRA), the centerpiece legislation of Roosevelt’s First New Deal, but it had no organizing mechanism and NIRA itself was struck down by the Supreme Court in early 1935.
That same year, Congress passed the National Labor Relations Act to repair problems in NIRA’s collective bargaining provisions and replace the struck-down NIRA bargaining system. The law was signed in July and immediately challenged by business groups; after the “switch in time that saved nine” — when swing justices on the Supreme Court switched from striking down expansive New Deal central planning to supporting it after President Roosevelt threatened to “pack” the Court by adding new New Deal-supporting members — the law was upheld in 1937.
In 2022 the Supreme Court agreed to hear the case Glacier Northwest vs. International Brotherhood of Teamsters Local Union No. 174, to the issue of “Does the National Labor Relations Act impliedly preempt a state tort claim against a union for intentionally destroying an employer’s property in the course of a labor dispute?”  The case involved an incident in 2017 in the state of Washington where the local union, IBT No. 174, organized a strike, leading to truck drivers employed by Glacier Northwest walking off the job site with concrete mixers being left in loading trucks still containing concrete. This led to the company hastily emptying the concrete from the trucks before the concrete hardened and resulted in damage to the trucks’ interiors.  Glacier Northwest’s suit alleges that the work stoppages were intentionally timed to cause damage to the trucks.  As of November 2022, the case’s outcome is pending. 
Passage of the National Labor Relations Act was followed by a substantial increase in both private-sector workforce unionization and labor union militancy. Strikes rose through 1937, and surged again after the 1937-38 recession, reaching an all-time high in 1943. The NLRB, empowered to uphold the Act, has used its power to independently create a body of law governing labor-management relations—some commentators have accused it of doing so “out of thin air.”
Passage of the Wagner Act upgraded and deepened the long-standing alliance between the labor unions and the Democratic Party. The old American Federation of Labor split in two, with John L. Lewis’s United Mine Workers of America leading a new coalition calling itself the Congress of Industrial Organizations (CIO). The CIO formed a committee (deceptively named the “Non-Partisan League”) to support President Roosevelt and his allies, who would keep the privileges unions won from the NLRA and appoint pro-union members to the NLRB. In the 1936 elections, the CIO and its member unions spent eight times what the AFL had spent on all national election campaigns from 1906 through 1928 combined.
Labor Management Relations Act of 1947
Also see Labor Management Relations Act of 1947 (Taft-Hartley Act) (Legislation)
In 1947, Congressional Republicans enacted a series of amendments to the National Labor Relations Act by overriding President Harry Truman’s veto. Known formally as the Labor Management Relations Act of 1947 and commonly as Taft-Hartley (after its sponsors, U.S. Rep. Fred Hartley (R-N.J.) and U.S. Sen. Robert Taft (R-Ohio)), the law sought to restore balance between labor unions, employers, and individual employees while combating union abuses that had expanded after the passage of the Wagner Act. Key provisions of the Taft-Hartley Act included a rule applying the NLRB’s adjudication of unfair labor practices to labor unions, a state option to allow employees who dissent from union activities not to pay for union activities (known as right-to-work), and a prohibition on union picketing against businesses not directly party to a labor dispute (known as secondary boycotts).
Labor Management Reporting and Disclosure Act of 1959
Also see Labor Management Reporting and Disclosure Act of 1959 (Legislation)
In the late 1950s, the NLRA was amended again after Congressional investigations uncovered substantial corruption of labor unions. The Labor Management Reporting and Disclosure Act of 1959—known as the Landrum-Griffin Act after its sponsors, U.S. Rep. Phillip Landrum (D-Georgia) and Sen. Robert Griffin (R-Michigan)—was enacted to give union members information about the financial dealings of their unions and to guarantee member involvement in unions’ internal governance. The Landrum-Griffin Act instituted a bill of rights for union members, which included protections of members’ right to speak out on union matters without interference, to run for local union offices in secret ballot elections, and to a fair internal union discipline process. The Landrum Griffin Act also established a series of disclosures that labor unions must file on their expenditures, reported on federal forms filed with the U.S. Department of Labor Office of Labor-Management Standards.
Healthcare Amendments 1974
In 1974, the NLRA was expanded to apply to nonprofit hospital workers, who had been included in the original Wagner Act but excluded by the Taft-Hartley Amendments. The 1974 amendments established stricter notice requirements for labor disputes at hospitals governed by the NLRA than at general employers.