* National Education Association (NEA): The NEA is the largest labor union in the United States representing educators, with more than 3 million members. It is a federation of state and local affiliates, representing teachers, paraprofessionals, and other school employees.
* Service Employees International Union (SEIU): The SEIU is one of the fastest-growing unions in the United States, representing more than 2.2 million workers. It is a union of healthcare, public sector, property service, and other workers.
* Teamsters Union (IBT): The IBT is a labor union representing workers in the transportation industry, with more than 1.4 million members. It is a federation of local unions, representing workers in trucking, warehousing, and other transportation-related jobs.
* United Automobile Workers (UAW): The UAW is a labor union representing workers in the auto industry, with more than 1 million members. It is a federation of local unions, representing workers at major automakers and parts suppliers.