Prior to the 1930s, shipyard workers had been organized into a number of craft unions affiliated with the American Federation of Labor (A. F. of L.). During the First World War, A. F. of L. unions flourished as the demand for wartime shipping led to an unparalleled expansion of the industry. Yet following the signing of the Armistice, government construction orders fell sharply and the industry entered a sustained period of economic stagnation. The massive layoffs that followed the collapse of the wartime boom rapidly depleted trade union membership, and the high unemployment accompanying the general postwar depression of 1920-1921 further undermined union power. It was at this time, moreover, that the various shipbuilding firms launched their "open shop" offensive in an effort to eliminate remaining trade union presence. By 1923, the employers had defeated the unions, and many established company-dominated unions to replace legitimate labor organizations.
Both the Great Depression and the rise of fascism in Europe in the early 1930s, however, brought about abrupt changes in the status of the shipyard workers. Confronted by severe, arbitrarily imposed wage reductions and the spread of massive unemployment accompanying the Depression, workers increasingly turned to unionism as a means of resistance. By September 1933, workers employed at the New York Shipbuilding Corporation in Camden, New Jersey, had organized an independent union which defeated the company union. And in March 1934, following a strike under the leadership of John Green, a sheetmetal worker and shipfitter who emigrated to the United States in 1923 from Clydebank, Scotland, this union won recognition and successfully negotiated immediate wage increases and improvements in working conditions. Other shipyard workers employed along the east coast soon joined in the struggle to achieve organization, and in September 1934, six locals met in Quincy, Massachusetts, to form the Industrial Union of Marine and Shipbuilding Workers of America (IUMSWA). The IUMSWA's subsequent organizational drive was thus propitiously launched at a time when the Roosevelt administration's preparations for the war against Nazism necessitated both the revival of naval shipbuilding and the rapid expansion of the merchant marine fleet.
The emergence of the IUMSWA marked a new departure in the nature of shipyard unionism. Like most of the new unions formed in the early thirties, the IUMSWA eschewed organization along craft lines, which would have created a separate union for each of the shipyard trades, and instead adopted the strategy of industrial unionism, by which all workers, irrespective of their particular trade or level of skill, were brought together into a single organization. In keeping with this "one union, one yard" plan of organization, the IUMSWA affiliated with the Committee for Industrial Organization (later the Congress of Industrial Organizations) in 1935. With the added strength provided by the CIO movement and the benefits of federally-supervised collective bargaining provided by the Wagner Act, the IUMSWA's bold organizing drives brought membership to well over 100,000 by 1940.
With the enormous expansion of shipbuilding during the Second World War, the Industrial Union of Marine and Shipbuilding Workers of America achieved unprecedented gains in both membership and influence. A major victory for the IUMSWA during the buildup of the national defense, 1940-1941, occurred when Local 15 secured an agreement with the Bethlehem Steel Corporation for workers employed at the firm's Hoboken, New Jersey, shipyard on May 15, 1941. This agreement effectively ended Bethlehem's maintenance of the open shop in shipbuilding, an industry which it had dominated throughout the prewar years, and prepared the path for the successful organization of that company's steel manufacturing plants by the Steel Workers Organizing Committee (SWOC-CIO). As membership reached 250,000 during the war years, IUMSWA officials held important posts in government agencies responsible for setting wartime labor policies. When the war stimulated steady membership growth in the more established east and west coast locals, the previously weaker locals in the South Atlantic and Gulf shipbuilding districts likewise experienced dramatic gains.
In the years immediately following the war, the IUMSWA suffered huge losses in membership, as the industry once again experienced rapid decline in the wake of demobilization. Although in the ensuing period, the IUMSWA launched campaigns to secure federal commitments to rebuild the nation's merchant marine, no such action was forthcoming. The Korean conflict (1950-1953) only temporarily reversed the general post-WWII slump in new ship construction. The decisions of U. S. investors to finance shipbuilding overseas severely undercut the union's efforts to maintain jobs in the later postwar decades. Indeed by 1973, the IUMSWA's membership had shrunk to approximately 21,000.
In the late 1970s and throughout the 1980s, the IUMSWA has concentrated its efforts on two major issues: 1) worker health and safety, and, 2) revival of the shipbuilding industry in the face of continued unfair trade practices by foreign builders, which have been bolstered by the willingness of U. S. companies to utilize foreign-built ships under American flags.
In attempting to extend worker control over issues of job safety and health, the IUMSWA has conducted several major studies to measure the effects of asbestos exposure and the harmful impact of exposure to various metals during such processes as welding and burning. The first Occupational Disease Study was begun at the Bethlehem-Key Highway yard in Baltimore, Maryland, directly under the auspices of Local 24 and the Mt. Sinai Medical Center. Additional studies have since been conducted at other major shipyards under IUMSWA contract.
The influx of foreign-built vessels into the American merchant fleet has led to massive layoffs in several important yards. In 1979, workers at Bethlehem-Sparrow's Point, Maryland, were hit with some 2,000 layoff slips. In addition to unemployment caused by merchant fleet usage of foreign-built ships, the IUMSWA has also had to deal with the Reagan administration's encouragement of foreign companies in producing material for the U. S. Navy. The problem of foreign competition was aggravated by the refusal of the Administration to provide the industry with the type of protections other governments have afforded to their home producers, especially heavy domestic subsidization. To counter the foreign-built problem, the IUMSWA has been working closely with the AFL-CIO Maritime Trades Department to secure much-needed legislation to make the market fair, and has successfully won application of the 1974 Trade Adjustment Act, which made workers laid off by unfair trade practices eligible for cash allowances, to the shipbuilding industry.
The IUMSWA has also been able to maintain union presence in related marine construction projects, including dredge building and offshore oil rig production, while at the same diversifying its membership to include city employees in Bath, Maine, fire equipment workers in West Virginia, employees in the New Jersey natural gas industry, and workers at an automobile dealership in Portland, Maine. Despite this diversification, the IUMSWA's membership numbers continued to decline, by approximately 50 percent, during the 1980s. The resultant financial difficulties led in part to the union's merger with the International Association of Machinists in 1988.