Arch-nationalist Henry Clay crafted the package of legislation that has become known as the Missouri Compromise. The dispute that led to the compromise revolved around the question of whether Missouri would be admitted to the Union as a free state (i.e. a state where slavery was illegal) or a state where slavery would be allowed. It was triggered by the Tallmadge Amendment, a provision in the House of Representatives that would have provided for gradual emancipation in the territory. The significance of the debate went beyond Missouri, though. Also at issue was the balance of slave and free states in the Senate as well as the larger question of whether slavery would be allowed to expand into the Louisiana Territory as a whole.
Clay's compromise called for the admission of Missouri as a slave state. To preserve the balance between slave and free states in the Senate, Maine would be admitted as a slave state at the same time. The issue of whether slavery would be allowed in the Louisiana Purchase was temporarily answered by drawing a line extending West on the map at 36'30 latitude (the northern border of Texas today.)
Henry Clay invented the Missouri Compromise.
Henry Clay was the creator of the Missouri Compromise.