Labor Unions Explained: Definition, History and Modern Examples

A labor union is an organized group of workers that bargains collectively with employers over pay, benefits and working conditions, using shared leverage that individual employees rarely have on their own. Roughly 14.4 million U.S. workers, about 10% of the workforce, belonged to one in 2023.

How a Union Actually Negotiates on Your Behalf

Unions run on dues and democracy. Members elect officers, pay dues, and those funds pay for the staff and lawyers who sit across the table from management. Most unions are chartered through one of two national umbrella groups, the American Federation of Labor and Congress of Industrial Organizations (AFL-CIO), formed in 1955, or the Change to Win Federation, which broke away from the AFL-CIO in 2005.

Federal law obligates an employer to bargain in good faith once a union is recognized, but it does not force the employer to accept any particular demand. A bargaining unit, essentially the union's negotiating team, goes through repeated rounds of talks with management until both sides sign a collective bargaining agreement. That contract spells out pay scales, sick days, vacation time, benefits and working conditions. Once signed, management cannot unilaterally alter it. When the contract expires, the two sides start over.

The NEA and Where Union Membership Is Concentrated Today

The National Education Association is the country's largest labor union, with nearly 3 million members. It covers public school teachers, substitute teachers, college faculty, support staff, administrators, retirees and students training to become teachers. The NEA negotiates with local and state school systems over wages and working conditions.

Government and public sector workers, teachers, police officers and firefighters among them, make up roughly a third of all union members nationally. Beyond education, unionization runs relatively high in utilities, transportation and warehousing, and entertainment.

Why Membership Has Fallen From a Third of Workers to About 10%

Union membership peaked in the 1950s, when nearly a third of American workers carried a card. It has slid steadily since, driven largely by the decline of domestic manufacturing, once a reliable source of blue collar union jobs. A 2023 Treasury report tied that decline in membership to widening income inequality between the middle class and top earners.

Legal changes have accelerated the trend. Right to work laws, now on the books in 27 states, bar contracts that require workers to join a union as a condition of employment. In 2018, the Supreme Court ruled in Janus v. American Federation of State, County, and Municipal Employees that public employees cannot be forced to pay dues supporting a union's collective bargaining work, even if they benefit from it. The House passed the Protecting the Right to Organize Act in March 2021 to make organizing easier and override right to work statutes, but it stalled in the Senate, where most Republicans opposed it and sent it to committee.

The Long Fight That Built Modern Labor Law

Organized labor in America predates the country itself. New York tailors staged what's considered the first strike in 1768 over a wage cut. The Federal Society of Journeyman Cordwainers, founded in Philadelphia in 1794, is generally regarded as the start of formal trade unionism. For much of the 19th and early 20th centuries, unions frequently excluded Black workers, women and immigrants, pushing those groups to organize separately. Membership today is more diverse, with growing representation among women, Black and Latino workers, though Asian workers remain underrepresented.

The Wagner Act of 1935 cemented the legal right to unionize, guaranteeing the right to strike and bargain collectively while creating the National Labor Relations Board to police unfair employer tactics. That law, more than anything else, is why collective bargaining became a fixture of American labor for the rest of the century.

The Arguments Against Certain Union Protections

Critics, including some business owners and think tanks, argue mandatory union membership interferes with free market competition, which is the rationale behind right to work laws. Police and teacher union contracts draw particular scrutiny for making discipline or termination difficult. A 2019 review of 656 police union contracts found 73% included an appeals process that gave arbitrators, chosen partly by the local union, final say over firing or disciplining officers, a structure researchers said had led to reversed punishments for abusive conduct.

Some labor activists have called for cutting police unions loose from broader labor coalitions over that record. The AFL-CIO's own 2020 recommendations on police reform argued for engaging police affiliates rather than isolating them. Separately, the Department of Justice notes that as of 2020 it had obtained relief in 24 civil racketeering cases involving unions affiliated with the Teamsters, the Laborers International Union of North America, the former Hotel Employees and Restaurant Employees International Union, and the International Longshoremen's Association.

Where Unions Fit in the Political Landscape

Unions endorse candidates, lobby on workplace safety and fund political campaigns, though the 2018 Janus ruling weakened their financial base for that work by ending mandatory dues from public sector nonmembers. The Democratic Party generally courts and wins union endorsements, while some unions, notably law enforcement groups, lean toward Republican candidates. Republicans have traditionally framed unions as a constraint on workplace freedom and have resisted measures like the PRO Act that would make organizing easier.