It is to Henry Clay (1777-1852) that the concept of the American System is most commonly attributed. Clay came on the political scene in the election of 1810 as an advocate of American national interests against the depredations of the British Empire at the time. As Speaker of the House of Representatives, he was a leading force behind the U.S. declaration of war against Britain in 1812.

Although he had actually voted to dissolve the Bank of the United States in his first term in Congress, in the period after the war, Clay realized that the very survival of the country depended upon implementing Hamilton’s economic program. Along with John Calhoun, Clay formulated an American System program which called for establishing a new National Bank, protecting U.S. industry with tariffs, and improving the U.S. economy and coherence with the building of infrastructure (at that point, canals and turnpikes).
Clay promoted this system as a Representative, Senator, Secretary of State, and a three-time candidate for the Presidency. Abraham Lincoln saw Clay, as leader of the Whig Party, as his mentor.

Further Reading:

See above, “The Startling American Revolution of Henry Clay and Mathew Carey,” by Anton Chaitkin.

Primary Sources:
“In Defence of the American System,” a series of speeches given in the U.S. Senate in 1832, reprinted in The Life and Speeches of Henry Clay, J.L. Gihon, Philadelphia, 1853, 2 vols.