Efficient markets are an essential factor in a nation's economic success. In the United States, as elsewhere, during the nineteenth century, rapid technological advances in transportation and communication reduced the costs of migration and created the potential for broader, and hence more efficient, markets. Realizing this potential, however, required the creation of institutions capable of channeling information between buyers and sellers and providing the means for market participants to act on that information. As the preceding narrative shows, employers and workers responded to the opportunities that falling transportation and communication costs created, constructing labor market institutions that helped to facilitate the massive redistribution of labor that American industrialization required. The increased geographic integration of labor markets in the nineteenth century contributed to the efficient allocation of labor, but it also produced a number of other unanticipated results with significant consequences for the course of American economic development.

Three important themes characterize the development of American labor markets in this period. First, despite the widely noted importance of friends and family in conveying labor market information, the extension of labor markets was accomplished largely through the active involvement of employers in recruiting labor. Second, although the channels of recruitment created by employers and workers facilitated the increasing geographic integration of labor markets over the course of the nineteenth century, market integration did not advance uniformly.