What is the National Labor Relations Act?
Unions get their legal standing from the National Labor Relations Act (NLRA) to provide collective bargaining leverage for workers with respect to workplace practices established by their employers. While you as an individual employee may not have much bargaining power, a union of employees has greater strength when negotiating with an employer as well as through the use of structured grievance procedures for resolving disputes. Your employer cannot interfere with your protected right to join or organize a union on behalf of co-workers and the employer cannot restrain or coerce you when you exercise your rights to promote a union.
Though it covers most workers, employees who are not covered include: railroad and airline employees, government employees, managers, farm workers, members of an employer's family, domestic workers, and independent contractors. Railroad and airline workers are covered under the Railway Labor Act, and Title VII of the Civil Service Reform Act regulates the work situations of the government employees excluded from coverage under the NLRA.