How was slavery mentioned in the northwest ordinance

The Northwest Ordinance was an act of the Congress of the Confederation of the United States, passed July 13, 1787. The ordinance created the Northwest Territory, the first organized territory of the United States, from lands beyond the Appalachian Mountains, between British North America and the Great Lakes to the north and the Ohio River to the south. The upper Mississippi River formed the Territory's western boundary. It was the response to multiple pressures the westward  expansion of America