During the nineteenth century, under free labor market contracting, apprenticeship persisted in Britain but declined in the United States. This article argues that apprenticeship endured in Britain because of its efficiency advantages and because of customs, inherited from the guilds, that favored training certification for entry into skilled jobs. By contrast, within the United States guild traditions were weaker, occupational certification was seldom required, and, as a result, indenture obligations were hard to enforce. Understandably, U.S. employers refrained from making training investments in potentially mobile apprentices.