Organizations through which workers combine to bargain collectively with employers, converting the powerlessness of the individual worker into shared strength. From early friendly societies and craft guilds through the industrial unions of the nineteenth and twentieth centuries to a contested present, unions have used collective bargaining, the strike threat, and political action to shape wages and conditions — while their economic and social effects remain genuinely debated.
A single worker who asks for higher pay can be fired and replaced by the next morning. A thousand workers who stop together cannot. That arithmetic is the whole idea behind a labor union. For two centuries, workers have combined to face employers as a group rather than one at a time. The fight to make that combination legal, and then to make it matter, runs through some of the hardest conflicts of the modern age.