the United States (also known as the national bank). Clay also supported the Bonus Bill of 1817, which would have provided a fund for internal improvements, but Madison vetoed the bill on constitutional concerns. Beginning in 1818, Clay advocated for an economic plan known as the "American System," which encompassed many of the economic measures, including protective tariffs and infrastructure investments, that he helped pass in the aftermath of the War of 1812. Monroe administration, 1817–1825 Like Jefferson and George Washington, President Madison decided to retire after two terms, leaving open the Democratic-Republican nomination for the 1816 presidential election. At the time, the Democratic-Republicans used a congressional nominating caucus to choose their presidential nominees, giving congressmen a powerful role in the presidential selection process. Monroe and Secretary of War William Crawford emerged as the two main candidates for the Democratic-Republican nomination. Clay had a favorable opinion of both individuals, but he supported Monroe, who won the nomination and went on to defeat Federalist candidate Rufus King in the general election. Monroe offered Clay the position of secretary of war, but Clay strongly desired the office of secretary of state and was angered when Monroe instead chose John Quincy Adams for that position. Clay became so bitter that he refused to allow Monroe's inauguration to take place in the House Chamber and subsequently did not attend Monroe's outdoor inauguration. In early 1819, a dispute erupted over the proposed statehood of Missouri after New York Congressman James Tallmadge introduced a legislative amendment that would provide for the gradual emancipation of Missouri's slaves. Though Clay had previously called for gradual emancipation in Kentucky, he sided with the Southerners in voting down Tallmadge's amendment. Clay instead supported Illinois Senator Jesse B. Thomas's compromise proposal in which Missouri would be admitted as a slave state, Maine would be admitted as a free state, and slavery would be forbidden in the territories north of 36° 30' parallel. Clay helped assemble a coalition that passed the Missouri Compromise, as Thomas's proposal became known. Further controversy ensued when Missouri's constitution banned free blacks from entering the state, but Clay was able to engineer another compromise that allowed Missouri to join as a state in August 1821. In foreign policy, Clay was a leading American supporter of the independence movements and revolutions that broke out in Latin America beginning in 1810. Clay frequently called on the Monroe administration to