The American System was necessary because it unified the nation, and created a strong, stable economy. To achieve these goals, the American System proposed the creation of a Tariff, the resurrection of the second National Bank, and construction of Internal Improvements ( Transportation).
Nationalism vs. Sectionalism
Nationalism is the belief that the people's loyalty should not be to a king or an empire but to a nation of people who share a common culture or history, patriots believed in nationalism. Sectionalism is a devotion to the interests of one geographic region over the interests of the country as a whole. Sectionalism is dangerous because people will have more loyalty to their own section of the country than they do to the nation as a whole.
What did the American System do?
This "System" consisted of three mutually reenforcing parts: a tariff to protect and promote American industry; a national bank to foster commerce (jointly owned by private stockholders and the federal government) ; and federal subsidies for roads, canals, and other "internal improvements" to develop profitable markets for agriculture.
Henry Clay (1777-1852)
Henry Clay was a war hawk, an American lawyer, politician, and skilled orator who represented Kentucky in both the United States Senate and House of Representatives. He was the leader of the Whig party and five times an unsuccessful presidential candidate. The American System became the chief plank in the platform of Clay’s Whig party, which was formed in opposition to the Democratic party of Andrew Jackson, creating ‘the second party system.’