The Missouri Compromise, also called the Commitment of 1820, was an agreement made in 1820 between the representatives of the slave and abolitionist states in the United States Congress in relation to the regulation of slavery in the Western territories, which in the future they would become states, to maintain the majority, or at least equality, of the number of states opposed to slavery, existing from the creation of the United States until then.
The Law of Kansas-Nebraska was the law promulgated in the United States, in 1854, for the creation of the states of Nebraska and Kansas, in territories of the old French Louisiana, but in which they remained some tribes of Indians. It was driven by the senator and leader of the Democratic party Stephen Arnold Douglas, of Illinois.
The situation of the two states north of the line defined in the Missouri compromise meant that both should be states in which slavery was not allowed. However, the contiguity of Kansas with the slave state of Missouri and the search by Senator Douglas for southern support for a railroad in his state caused the law to include the provision that, in order to decide on the issue of slaves, citizens could exercise "popular sovereignty" and, therefore, be able to decide whether to be a slave state.
The Kansas-Nebraska Act effectively nullified the Missouri Compromise of 1820, and although it failed to make Kansas a state with legal slave labor, it further opened up the nation's divisions that led to the Civil War of 1861.
