Following a perceived victory in the War of 1812, the surge of nationalistic spirit that swept the nascent U.S. nation revealed its significance as a catalyst for unified change. The nationalism manifested itself economically, socially and politically, and was evident through the emergence of a uniquely American culture. The first major political and economic policy change was the emergence of Henry Clay’s American System. The system created an expansive, accessible credit institution, protectionist tariff act, and an invigorated investment in infrastructure (Kennedy 256). The motive for the new policy was the desire to lessen American dependence on cheap British imports. In establishing related acts such as the Tariff of 1816, the nationalist Congress acted directly in the interest of protecting American infant-industries, rather than acting purely from the consumer’s pricing interest. Furthermore, the national bank whose charter had expired was reinstated in an effort to bring in more revenue to the federal government (Kennedy 256). In line with the American System, revenues from tariffs would be allotted to the creation of new transportation methods, such as the Erie Canal (Kennedy 257). However, sectionalism was still present, as states opposed federal funding of interstate commerce, especially those of New England and the Hartford Convention. Despite the sectionalism, an American culture did arise, as seen through the literature of Washington Irving and American-written textbooks (Kennedy 256). Furthermore, America was able to defensively assert its intentions in the Western Hemisphere under the Monroe Doctrine.
Although the new American identity unified the country, it was partially built on the unfortunate issue of slavery that would arouse the sectionalist differences between North and South in the years after the Missouri Compromise.