• The Northwest Ordinance of 1787 prohibited the introduction of slavery into the area bounded by the Ohio River and the Mississippi. Such and ordinance was confirmed by the First Congress elected under the Constitution and did not apply to areas south of the Ohio River.

• 1803, President Jefferson acquired the Louisiana Territory by a treaty – after ratified by the Senate.

• The slavery question got its height in 1817 when Missouri (South) applied for admittance to the Union. The practice of appliance was normal for a state that had reached a certain number of inhabitants, but Missouri rose the matter of admittance of a free or slave state.

• At the time of their independence from Great Britain, in the thirteen colonies slavery existed throughout, but step by step it ceased being a national institution. In fact at the beginning of the 19^th century it had become a peculiarity of the South that needed it for running its plantations, in spite of the trend issued by the Northwest Ordinance. However it might be argued slavery existed only in those states where some positive laws recognized it and protected it, while the absence of a precise slave code would force slave-holders to lose their property in slaves.

• By the time of Missouri’s appliance the free state and the slave state were both numbered eleven.

• Missouri asked for the possession of slaves: if it had been admitted, the slave states would have been the majority in the Senate and, consequently, in a vetoing position against the proposals and interests of the North in the House of Representatives.

• 1820, H. Clay eventually worked out a compromise in Congress when allowing Maine to join the Union as free states and Missouri as a slave one.

• Meanwhile Congress outlawed slavery from the Louisiana Purchase Territory north of Missouri’s southern border, that is to say latitude 36° 30’, or "Mason-Dixon line" (from the names of the two British astronomers which determined it in 1763-7).

• The free states were twelve, just like the slave ones: the antagonism was actually marked and Jefferson (now retired) commented the growing conflict between the two parts as a sign of an imminent disaster. He blamed slavery, but – at the same time – he understood the importance of it for the social and economic life of the South.

 torna alla mappa concettuale