The Northwest Ordinance was created with the purpose of colonizing vast areas of land to the west of the northern original colonies of the USA. The creation of the Northwest Territory was its most important consequence. It set precedent that the westward expansion of the USA would be accomplished by the creation of new states out of those lands rather than absorbing them into already existing states. It forbade slavery in the territory and thus also set the precedent that the Ohio River would be the border between northern free states and southern slave states. It would result in a continuous struggle for supremacy every time a new state would be admitted into the Union since both free and slave states would struggle to add such state to their group of free or slave states. Most specifically, its article 6 stated that:
- "Art. 6. There shall be neither slavery nor involuntary servitude in the said territory, otherwise than in the punishment of crimes whereof the party shall have been duly convicted: Provided, always, That any person escaping into the same, from whom labor or service is lawfully claimed in any one of the original States, such fugitive may be lawfully reclaimed and conveyed to the person claiming his or her labor or service as aforesaid."
Therefore, not only does this article prohibits slavery in the northwest territory, it allows for its continuance south of this boundary (Southern Slave States) and even includes a provision allowing for the pursuit and capture of any runaway slaves.
