Congress, under the Articles of Confederation, enacts the Northwest Ordinance, establishing rules for governing the Northwest Territory, for admitting new states to the Union and limiting the expansion of slavery.
Considered to be one of the most significant achievements of the Congress of the Confederation, the Northwest Ordinance of 1787 put the world on notice not only that the land north of the Ohio River and east of the Mississippi would be settled but that it would eventually become part of the United States. Until then this area had been temporarily forbidden to development.
Increasing numbers of settlers and land speculators were attracted to what are now the states of Ohio, Indiana, Illinois, Michigan and Wisconsin. This pressure together with the demand from the Ohio Land Company, soon to obtain vast holdings in the Northwest, prompted the Congress to pass this Ordinance
The area opened up by the Ordinance was based on lines originally laid out in 1784 by Thomas Jefferson in his Report of Government for Western Lands. The Ordinance provided for the creation of not less than three nor more than five states. In addition, it contained provisions for the advancement of education, the maintenance of civil liberties and the exclusion of slavery.
Above all, the Northwest Ordinance accelerated the westward expansion of the United States.
The Constitution was adopted on September 17, 1787, by the Constitutional Convention in Philadelphia, Pennsylvania, and ratified by conventions in each U.S. state in the name of "The People". The Constitution has been amended twenty-seven times; the first ten amendments are known as the Bill of Rights (From Wikipedia)