Union security

Union Security is the enactment of various policies in an employer-union agreement to ensure the union's continued survival. "Closed shops," in which the company may only employ union workers, were outlawed in the Taft-Hartley Act over president Truman's veto. However, "Union shops," which require new employees to join the union within 30 days, are allowed (with some exceptions, for example those expelled from the union and those with religious objections to unions must be exempted).

All union security arrangements can be and have been outlawed by the states by so-called "Right-to-work laws".