Very early in its history, the Board was confronted with conflicting claims by craft unions and industrial unions for the right to represent craft workers. Generally, the industrial unions sought a broad unit of production and craft workers, whereas the craft unions sought units of their particular skill. The Board's first reaction was to establish broad units where it appeared that one union had a majority throughout the plant. In doing so, the Board relied heavily upon what it considered best for collective bargaining purposes. In many cases, the Board created large units over the protests of small groups on the basis that the larger unit would best serve the interests of the majority by insuring to them the fullest benefits of the act through the promotion of effective collective bargaining and peaceful labor relations.
Dallas L. Jones,
Self-Determination vs. Stability of Labor Relations: The Effect of American Potash,
Mich. L. Rev.
Available at: https://repository.law.umich.edu/mlr/vol58/iss3/2