Being a part of the Louisiana Territory which under France extended over the whole Mississippi Valley as far as the Allegheny mountains, it was governed by the same colonial regulations.[9] Slavery, therefore, had legal standing in this territory.
When Antoine Crozat, upon being placed in control of Louisiana, was authorized to begin a traffic in slaves, Crozat himself did nothing to carry out his plan.

But in 1717 when the control of the colony was transferred to the _Compagnie de l'Occident_ steps were taken toward the importation of slaves.

In 1719, when 500 Guinea Negroes were brought over to serve in Lower Louisiana, Philip Francis Renault imported 500 other bondsmen into Upper Louisiana or what was later included in the Northwest Territory.

Slavery then became more and more extensive until by 1750 there were along the Mississippi five settlements of slaves, Kaskaskia, Kaokia, Fort Chartres, St.Phillipe and Prairie du Rocher.[10] In 1763 Negroes were relatively numerous in the Northwest Territory but when this section that year was transferred to the British the number was diminished by the action of those Frenchmen who, unwilling to become subjects of Great Britain, moved from the territory.[11] There was no material increase in the slave population thereafter until the end of the eighteenth century when some Negroes came from the original thirteen.
The Ordinance of 1787 did not disturb the relation of slave and master.
Some pioneers thought that the sixth article exterminated slavery there; others contended that it did not.

The latter believed that such expressions in the Ordinance of 1787 as the "free inhabitants" and the "free male inhabitants of full size" implied the continuance of slavery and others found ground for its perpetuation in that clause of the Ordinance which allowed the people of the territory to adopt the constitution and laws of any one of the thirteen States.