dec 31, 1786 - 1787: Congress passed the Northwest Ordinance of 1787.

Description:

To end this confusion, Congress passed the Land Ordinance of 1785, under which western lands were divided into six-mile squares called townships. Each township was then divided into 36 sections of 640 acres each. One section of each township was set aside to support the township's public schools and the others sold to settlers.