The labor movement in the United States is a broad social and economic phenomenon encompassing the organized efforts of workers to improve wages, hours, working conditions, and legal protections through collective action. It includes trade unions, industrial unions, federations, labor political activity, and related reform movements spanning from the early industrial period to the present. The movement has involved workers across a wide range of industries, skill levels, and demographic backgrounds, and has intersected with major episodes in American political, legal, and economic history.

The roots of organized labor in the United States extend to craft guilds and journeymen's associations in the late eighteenth and early nineteenth centuries. The movement expanded significantly during industrialization, giving rise to national federations, industry-wide strikes, and sustained legislative campaigns. Major organizations have included the Knights of Labor, the American Federation of Labor (AFL), the Industrial Workers of the World (IWW), the Congress of Industrial Organizations (CIO), and — following a 1955 merger — the AFL-CIO. The latter half of the twentieth century saw union membership in the private sector decline substantially, even as public-sector unionization grew. For a fuller account, see United States Labor Movement — History.

The legal framework governing labor relations has changed repeatedly over time. Landmark legislation includes the Norris–LaGuardia Act (1932), the National Labor Relations Act (1935, also known as the Wagner Act), the Labor Management Relations Act (1947, also known as the Taft-Hartley Act), and the Labor-Management Reporting and Disclosure Act (1959, also known as the Landrum-Griffin Act). These statutes defined workers' rights to organize and bargain collectively, established the National Labor Relations Board (NLRB), and imposed regulatory requirements on both unions and employers. State-level right-to-work laws, authorized under Taft-Hartley, further shape the legal landscape in more than half of U.S. states.

Union membership as a share of the total workforce peaked at approximately 35 percent in the mid-1950s and had fallen to roughly 10 percent by the early 2020s, with private-sector density below 7 percent and public-sector density near 33 percent. The causes and consequences of this decline are subjects of ongoing debate. See Union Decline — Debate.

Economists and labor historians broadly agree on several descriptive facts: that union membership in the United States has declined significantly since its mid-twentieth-century peak; that unionized workers have historically earned higher wages on average than comparable non-union workers; and that the legal framework established in the 1930s fundamentally reshaped labor relations. The causes of union decline, the net economic effects of unionization, and the normative question of whether union density should be higher or lower are all contested. See Labor Movement — Economics Consensus.

Pro-Labor / Expansionist View: Proponents of stronger unions argue that collective bargaining is a necessary counterweight to employer market power, that union decline has contributed to wage stagnation and rising income inequality, and that legislative and structural barriers have limited worker organizing. See Pro-Labor Viewpoint.

Free-Market / Voluntarist View: Critics of compulsory unionism and expansive labor regulation argue that unions can distort labor markets, reduce economic efficiency, protect incumbent workers at the expense of outsiders, and concentrate political power in union leadership. See Free-Market Viewpoint.

Syndicalist / Radical View: Some labor activists and theorists argue that the dominant model of business unionism — focused on wages and contracts within the existing economic system — is insufficient, and that labor should pursue broader structural transformation of the economy or society. See Syndicalist Viewpoint.

Conservative / Traditionalist View: A distinct strand of conservative thought has supported certain forms of craft unionism and worker association while opposing industrial unionism, public-sector unions, or union political activity. See Conservative Viewpoint.

• United States Labor Movement — History
• Union Decline — Debate
• Labor Movement — Economics Consensus
• Pro-Labor Viewpoint
• Free-Market Viewpoint
• Syndicalist Viewpoint
• Conservative Viewpoint
• Public-Sector Unions in the United States
• Collective Bargaining
• National Labor Relations Act
• Taft-Hartley Act
• Right-to-Work Laws
• AFL-CIO
• Industrial Workers of the World
• Strikes in the United States

1. Bureau of Labor Statistics, U.S. Department of Labor. Union Members Summary. Issued annually. https://www.bls.gov/news.release/union2.nr0.htm
2. Melvyn Dubofsky and Foster Rhea Dulles. Labor in America: A History. 8th ed. Wheeling, IL: Harlan Davidson, 2010.
3. Christopher L. Tomlins. The State and the Unions: Labor Relations, Law, and the Organized Labor Movement in America, 1880–1960. Cambridge: Cambridge University Press, 1985.
4. National Labor Relations Act, 29 U.S.C. §§ 151–169 (1935).
5. Labor Management Relations Act, 29 U.S.C. §§ 141–197 (1947).
6. Richard B. Freeman and James L. Medoff. What Do Unions Do? New York: Basic Books, 1984.
7. Barry T. Hirsch. “Sluggish Institutions in a Dynamic World: Can Unions and Industrial Competition Coexist?” Journal of Economic Perspectives 22, no. 1 (2008): 153–176.