Dockworkers have power. Often missed in commentary on today’s globalizing economy, workers in the world’s ports can harness their role, at a strategic choke point, to promote their labor rights and social justice causes. Peter Cole brings such overlooked experiences to light in an eye-opening comparative study of Durban, South Africa, and the San Francisco Bay Area, California. Path-breaking research reveals how unions effected lasting change in some of the most far-reaching struggles of modern times. First, dockworkers in each city drew on longstanding radical traditions to promote racial equality. Second, they persevered when a new technology–container ships–sent a shockwave of layoffs through the industry. Finally, their commitment to black internationalism and leftist politics sparked transnational work stoppages to protest apartheid and authoritarianism. Dockworker Power not only brings to light surprising parallels in the experiences of dockers half a world away from each other. It also offers a new perspective on how workers can change their conditions and world.