Impact of the Market Revolution on Labor

During the Market Revolution in the early 19th century, a significant transformation occurred in the United States concerning economic practices, labor structures, and social organizations. This era saw the rise of new transportation technologies, the growth of regional specialization, and a shift from subsistence farming to a market-oriented economy. Several factors contributed to these changes, including advancements in infrastructure, the expansion of the factory system, and demographic shifts. Given these dynamics, which of the following developments was most directly the result of the Market Revolution?