This article analyzes labor unrest in Indonesian harbors in the crucial first year of independence. It concludes with the Indonesian government's decision in February 1951 to ban strikes in vital industries and establish a formal arbitration system. The focus is on conflicts in the Java harbors of Jakarta, Semarang, and Surabaya, and Sumatra's east coast harbor of Belawan. Conflict in the harbors illustrates both the agency of workers and the strategic and tactical astuteness of unions. The impetus for industrial action emerged from the workers themselves, not from outside agitators as often stated. Unions were managers of worker discontent, mobilizing it into industrial campaigns that forced employers to enter into collective agreements. By the end of the year, unions' strategy of campaigning in one harbor at a time in a form of pattern bargaining had significantly improved dockworkers' wages and conditions and created greater uniformity across companies and harbors. By the end of the year, unions had forced employers to sign collective agreements that included much greater standardization of wages and conditions. The minimum wage for day-wage laborers increased between 2.5 and 3 times—more than compensating for inflation—and there was substantially increased in-kind benefits, too, including a larger rice allowance, free medical care, and at least two free meals daily. Moreover, the collective agreements included clauses on overtime rates, maximum hours of required work each day, and wages paid for work on Sundays. Unions were formally recognized and employers' rights to dismiss workers were constrained. These legally enforceable collective agreements, unheard of in the colonial era, combined with new labor laws promulgated during the year to greatly improve the dockworkers' lot.