Even as regional economies ensured economic interdependence, they highlighted political differences. For instance, the growth in trade between regions led to an increase in commercial institutions, such as banks, the largest of which were established in the North. When the nation’s first severe recession hit in 1819, many southern planters and midwestern farmers blamed it on the banks. In reality, falling prices for cotton and wheat abroad as well as overextension of credit by U.S. banks contributed to the recession. Whatever the cause, the interdependence of regional economies ensured that everyone suffered. At the same time, these economies were built on distinct forms of labor, with the South becoming more dependent on slavery and the North less so. When Missouri, situated between the old Northwest Territory and expanding southern cotton lands, applied for statehood in 1819, these regional differences set off a furious national debate over slavery.