The American System was a program for economic development championed in the era following the War of 1812 by Henry Clay, one of the most influential members of Congress in the early 19th century. Clay's idea was that the federal government should implement protective tariffs and internal improvements and a national bank should help develop the nation's economy.
Clay's basic argument for the program was that by protecting American manufacturers from foreign competition, ever-increasing internal markets would spur American industries to grow. For example, people in the Pittsburgh region could sell iron to the cities of the East Coast, in place of iron which had been imported from Britain. And various other regions of the country sought protection from imports which could undercut them in the marketplac