For centuries, the maritime cargo passing through the port of Barcelona was handled by the men of a half-dozen guilds. Collectively, these ancient corporations enjoyed monopolistic privileges over the various types of cargo and areas of operation—in the shallow harbor, to and from the Customs House, and throughout the city and beyond. At the end of the eighteenth century, the advances of economic and political liberalism began to question, challenge, and eventually dismantle the guild structure: a process that came to fruition in the early nineteenth century with the abolition of most guilds throughout Spain. However, some of the cargo-handling guilds had been defended by the Navy against abolition until the second half of the nineteenth century, when their orderly world collapsed into competitive companies able to hire men of their choosing (former guildsmen or otherwise). In this article, we look at the harbor-based guilds and the process by which guildsmen became the unorganized workers and capitalistic directors of the new dockworker companies. We offer a vision of the transformation of the guild system into a private system for organizing the labor of maritime-cargo handling. In this account, we examine technological changes in the means of production, changes in the organization of labor, the appearance of a new capitalist class in the sub-sector, and the rise of a capitalist mode of production based on the proletarianization of cargo handling.