In these ways slavery had ceased to be a vital institution north of Maryland and Kentucky. Why should slavery be allowed west of the Mississippi River? Louisiana had been admitted as a slave state (1812). But the admission of Louisiana had been provided for in the treaty for the purchase of Louisiana from France. The Southerners felt as strongly on the other side. They said that their slaves were their property, and that they had a perfect right to take their property and settle on the land belonging to the nation. Having founded a slave state, it was only right that the state should be admitted to the Union.
通过这些努力，在马里兰和肯塔基北部已经不存在有效的奴隶制机构，为什么在密西西比河西部还要允许有奴隶制？1812年路易斯安那已经作为一个奴隶制州被美国接受，因为从法国购买路易斯安那的条约中已经规定美国接受路易斯安那为一个州，南方各州的人则认为不然，他们说奴隶是他们的财产，他们完全有权力带着他们的财产到属于美国的土地上定居；既然已经形成了一个奴隶州，所能做的选择只能是接受它为联邦的一个州。
279. The Missouri Compromise, 1820.-When the question of the admission of Maine and Missouri came before Congress, the Senate was equally divided between the slave states and the free states. But the majority of the House of Representatives was from the free states. The free states were growing faster than were the slave states and would probably keep on growing faster. The majority from the free states in the House, therefore, would probably keep on increasing. If the free states obtained a majority in the Senate also, the Southerners would lose all control of the government. For these reasons the Southerners would not consent to the admission of Maine as a free state unless at the same time Missouri was admitted as a slave state. After a long struggle Maine and Missouri were both admitted-the one as a free state, the other as a slave state. But it was also agreed that all of the Louisiana purchase north of the southern boundary of Missouri, with the single exception of the state of Missouri, should be freesoil forever. This arrangement was called the Missouri Compromise. It was the work of Henry Clay. It was an event of great importance, because it put off for twenty-five years the inevitable conflict over slavery.
279．《密苏里折中案》（1820年）--当国会遇到接受缅因与密苏里为两个州这个问题时，参议院被分为奴隶州和自由州两个等同的部分，但是，大多数众议员都是从自由州而来，自由州比奴隶州发展要快，而且可能会继续快速发展，因此，众议院来自自由州的大部分议员的数量可能保持增长，如果自由州也在参议院获得大多数席位，南方人将失去对政府的控制。由于这些原因，除非将密苏里作为一个奴隶州而接受，南方人不会同意接受缅因为一个州。经过长时间的斗争，缅因和密苏里都被接受下来，它们一个是奴隶州，一个是自由州。但是，国会还达成一致的是，密苏里南部边界以北所买来的那些路易斯安那地区（密苏里州除外）都应该永远没有奴隶制。这个协议被称为《密苏里折中案》，它是亨利o克雷的杰作。这是一个重要的历史事件，因为它将关于奴隶制的战争向后推迟了25年。